Andy,
Hopefully, you've already solved your stuck collet problem. If not, this method has always worked for me. Tightly wrap the bit top with a shop rag to protect the cutters - about 5 turns. Place the collet wrench on the nut and use a small "pipe wrench", placed around the wrapping. Wrench handle should be on your right. Use the tightened wrench to turn the bit, clockwise. When the bit moves, reverse the wrench (handle on your left) and turn it counterclockwise. Also, apply a slight pulling pressure with each movement to remove the bit. Repeat process, until bit is out of the collet. A small pipe wrench gives a firmer grip than a crescent and is less apt to tear through the rag, causing cutter damage. It's also a good idea to have a helper hold the router while you perform the task.
-Bob