I have a trinity plus so here we go. Go to the drum block with the cursor and switch it to midi, to the right turn off to 1a, in program turn off till you see 1. You go from 1 to 128. set the program you want and record the track. Track 2 would be 2a and so on. make sure your trinity is on sequencer mode. midi in 1 on mpc to midi out on trinity, midi in on trinity to midi out a on mpc. good luck.
peace