Syncronised time stretching or bpm changing...

Hey guys
 
doing a remix, the drums seem live, but seem to change bpm by about 3-4bpm for differing sections (I'm not going to be using the original drums, just using them as the gage for the vocals and other tracks)...
 
Not used to editing audio in Sonar... (Using 8)
 
What are the various and easiest ways I can go about  time stretching the audio to fit the tempo??
 
I will be slowing it by about 4-3bpm... will this f*** up the sound too much?
 
I'll probably be chopping parts up to move them about, just wanna see what's easiest way to get it closest before drastic chopping.
 
Thanks.