I usually assign a key on my keyboard to be my "splitting" tool--sorry, totally forgot what the name of the function is.
I then play the track, and as long as the audio track I want to chop is selected, pressing the splitting key I've assigned will "split" the track when I tell it to. Therefore, I can split at a verse, a hit, a snare..whatever I want.
After I've split, or chopped up, the song, I just open an EXS, click on "edit" to open it's editor, and then I drag and drop the samples in.
I've done this for years now in Logic, and to me, it's the best way because I still haven't found an accurate way to accurately chop a song using "convert to new sampler instrument."
I believe this way is also explained by Just Blaze on youtube--sorry for a shitty response...but we both have the same method and it's quite easy.
This also allows me to rearrange pieces of the audio track if I deem it easier per track over replaying samples through EXS...