Multiple LilyPond Versions

[PMA]

Hi List.

I've downloaded an old LilyPond version (lilypond-2.10.33-1.linux-x386.sh)
to correct some details in an old .ly score that the 2.12 & 2.13.. versions
just won't stand for.

The .sh is sitting now in an isolated directory.  Before executing it, I 
want
to ensure that doing so won't overwrite or otherwise clobber my existing
LilyPond setups.

How can I control the installation-process's file distribution?

Thanks in advance.
Pete

P.S.  In my new Linux upgrade, I can't recall how I managed this issue
        on my old system -- or even whether I did, beyond getting lucky.