Matt Pearce

Hi Guys Really new to cakewalk. So i have a midi track of a commercial song which i want to use for myself to learn the guitar solos etc.. so there is a piano midi track1, and its some real ropey epiano synth. I have a copy of ivory Yamaha vsti. how/can i even change the instrument on this midi channel to use the ivory vsti??? sorry for lame question, i have been googling but not rally found what im looking for. thank you