You only have to remove a small amount, just enough to let the new action drop in, then mix up some epoxy and re-bed it. Don't overthink it. No need to hog out a gross amount of the old bedding, especially if the action going in is the same make/model as it was previously bedded for. Not a "four minute job" but not especially difficult.
If there are areas that are already undersize for the new action, simply wash it with acetone to remove whatever amine blush may remain from the first bedding job (and residual oils) and scuff it to provide a good adhesion surface for the new epoxy.
This ^^^
