Safely removing unused Grub2 from MBRs & boot sectors, veirfying still bootable?

[albion]

Now that I've got *install* figure out, and an upgraded BIS that reports my 
system info correctly ...

I want to remove Grub2 from a couple of places on a system.  After reading a 
bunch of 3rd party posts about it I'm 100% sure it's possible to BADLY screw 
this up.

So I'm gonna <noob>ASK!</noob> here.

My system runs Grub2.  The OS is on a RAID-1 array.

        cat /proc/mdstat
                Personalities : [raid1] 
                md0 : active raid1 sdc1[1] sda1[0]
                      1048512 blocks super 1.0 [2/2] [UU]
                      bitmap: 0/1 pages [0KB], 65536KB chunk

                md1 : active raid1 sda2[0] sdc2[1]
                      487205888 blocks super 1.2 [2/2] [UU]
                      bitmap: 3/4 pages [12KB], 65536KB chunk

I've also got an additional drive used for LVM mounts.

I want to LEAVE Grub2 installed in the MBRs for the raid disks, /dev/sda & 
/dev/sdc

I want to REMOVE Grub2 from:

        -- the boot sectors of the raid disks' partitions, /dev/sda1 & /dev/sdc1
        -- the MBR of the nonOS, additional drive, /dev/sdb

And,  most importantly, I want to make sure that the system still boots after, 
using "just" the MBR-installed Grub info on the RAID disks.

What's the recommended process for removing that unused data and verifying that 
I'll still be bootable?

JerryG

Fyi, 'bootinfoscript' currently reports

        cat ~/RESULTS.txt 
                                  Boot Info Script 0.76      [13 April 2017]


                ============================= Boot Info Summary: 
===============================

                 => Grub2 (v2.00) is installed in the MBR of /dev/sda and looks 
at sector 1 of 
                    the same hard drive for core.img. core.img is at this 
location and looks 
                    for (mduuid/f36d5988500d33cd1434cb8824a14c13)/grub2. It 
also embeds 
                    following components:
                    
                    modules
                    
---------------------------------------------------------------------------
                    fshelp ext2 part_msdos diskfilter mdraid1x biosdisk
                    
---------------------------------------------------------------------------
                 => Grub2 (v2.00) is installed in the MBR of /dev/sdb and looks 
at sector 1 of 
                    the same hard drive for core.img. core.img is at this 
location and looks 
                    for (mduuid/f36d5988500d33cd1434cb8824a14c13)/grub2. It 
also embeds 
                    following components:
                    
                    modules
                    
---------------------------------------------------------------------------
                    fshelp ext2 part_msdos diskfilter mdraid1x biosdisk
                    
---------------------------------------------------------------------------
                 => Grub2 (v2.00) is installed in the MBR of /dev/sdc and looks 
at sector 1 of 
                    the same hard drive for core.img. core.img is at this 
location and looks 
                    for (mduuid/f36d5988500d33cd1434cb8824a14c13)/grub2. It 
also embeds 
                    following components:
                    
                    modules
                    
---------------------------------------------------------------------------
                    fshelp ext2 part_msdos diskfilter mdraid1x biosdisk
                    
---------------------------------------------------------------------------

                sda1: 
__________________________________________________________________________

                    File system:       linux_raid_member
                    Boot sector type:  Grub2 (v1.99-2.00)
                    Boot sector info:  Grub2 (v1.99-2.00) is installed in the 
boot sector of 
                                       sda1 and looks at sector 290367 of the 
same hard drive 
                                       for core.img, but core.img can not be 
found at this 
                                       location.

                sda2: 
__________________________________________________________________________

                    File system:       linux_raid_member
                    Boot sector type:  -
                    Boot sector info: 

                sdb1: 
__________________________________________________________________________

                    File system:       LVM2_member
                    Boot sector type:  -
                    Boot sector info: 

                sdc1: 
__________________________________________________________________________

                    File system:       linux_raid_member
                    Boot sector type:  Grub2 (v1.99-2.00)
                    Boot sector info:  Grub2 (v1.99-2.00) is installed in the 
boot sector of 
                                       sdc1 and looks at sector 290367 of the 
same hard drive 
                                       for core.img, but core.img can not be 
found at this 
                                       location.

                sdc2: 
__________________________________________________________________________

                    File system:       linux_raid_member
                    Boot sector type:  -
                    Boot sector info: 

                md1: 
___________________________________________________________________________

                    File system:       LVM2_member
                    Boot sector type:  -
                    Boot sector info: 

                md0: 
___________________________________________________________________________

                    File system:       ext4
                    Boot sector type:  Grub2 (v1.99-2.00)
                    Boot sector info:  Grub2 (v1.99-2.00) is installed in the 
boot sector of 
                                       md0 and looks at sector 290367 of the 
same hard drive 
                                       for core.img, but core.img can not be 
found at this 
                                       location.
                    Operating System:  
                    Boot files:        /grub2/grub.cfg /grub2/i386-pc/core.img