What do you guys use to change a sample? In the Mac world I use this audio sdk program/garageband to slow/speed up a file, then I import it into Reason 4.0.
What can I use in Windows? All I have is Reason 4.0...
Use Recycle. Set your markers then you can change the tempo or time stretch. When you export it from recycle you can load it into Dr. Rex and it'll sync to the tempo of your song in Reason.
However you want to do it Recycle will get you there.