Originally Posted by
NukeouT
It is a 21" frame, and it came with 165mm crank. As a taller rider I got a taller stem and raised the seat to the max mark. I also replaced that crank with a longer 170mm one.
Sounds like your frame may be too small for you?
But anyway, back to your question. If the QR wheel fits in your dropouts now, you can just swap the axles. If you've never disassembled and regreased bearings before, this should be all you need:
http://sheldonbrown.com/tooltips/hubs.html
Once you get everything apart it should be obvious how to swap axles and reassemble.