Question Kill-ring modify last entry.

[Ergus]

Hi:

I have been reading the elisp documentation and it is unclear for me if
there is a "canonical" (lets say formal/supported/provided/save)
function to replace the last entry in the kill-ring with a new one (like
the append option).

I have been playing with `current-kill` or just making (pop kill-ring)
before killing again but maybe there is a better alternative?

Thanks in advance,
Ergus