SONAR 8 producer assigning drum sounds to midi file

Hi guys,  newbie here, just learning Sonar 8...
 
I have a midi file recorded/set up to play a single drum sound (i.e.  kick).  Can someone possibly walk me thru the steps from importing/opening the midi file in Sonar 8 to assigning a specific (kick) drum sound from Session Drummer 2 ?  
Ultimately, I need to be able to load and set up 8 midi tracks, each with an assignable drum sound for each one.  I need to be able to select which drum sound I want on each track.
Do I need to get some other drum sound VST or something... ?   Want really good quality drum sounds.
Thanks much for your help !