Apple Logic Pro /LogicExpress Discussion

I'm brand new to Logic and I'm hitting my first "wall." I want to edit an audio drumset loop - not the file attributes per se, but the actual pattern being played - so that the loop better fits the song I'm working on.
Is this possible? If so, how do I do this? Can an audio loop be converted to a midi file so that I can edit it like I would a midi drumset loop (which I DID figure out how to do)?