If you have a few bucks to spend, don't mind voiding your warranty and want to learn something, then don't bother with cutting and soldering, visit these guys and buy the tools and stuff to re-terminate them yourselves at the length you need. Shortening is always easier than lengthening.
Molex Pins : Performance-PCs.com, ... sleeve it and they will come
Pick up the connectors you need, a crimping tool (pliers can work but aren't as good), some strippers (wire not women), shrink wrap, and heat gun (hari dryer in a pinch).
Cut the wires at the length you want, slide on a small piece of shrink wrap, crimp on the terminals, slip back on your connectors, heat the shrink wrap once in place and you're done. Easy as pie.
Oh, you'll need a removal tool to pull the old terminals from the stock connectors, i use a sanded down paper clip to pinch them. Found they were stronger than the stock ones. YouTube molex pins remover and you'll find a dozen tutorials. This way you dn't have any solder connections.