Tony Miro would be the man to ask bro but I'll give it a shot. In Reaper, split the take where you want to change the tempo. Once you have the take split, right click on the part you want to change. Select item properties. You will see the tempo. Let's say you recorded at 130bpm that would be the 1.0 setting. To increase, go up on this number. Keep in mind though that while it try's to preserve pitch, it will change.
I would post this question in the Recording forum also, maybe get more feedback.