No it's already like that. It's a VERY cool bow, when you pull on the string the two pullies (I'm sure they're called something else, but I don't know) both rotate and when you let go of the string they rotate back and pull everything back into starting position.
They are called "cams".
It looks great. You can probably disassemble them and repaint the bow.
Bows are usually a dark colour for stealth reasons.