The pipes are sweated into the base of the unit. What you need to do is get all the plastic off of it, and heat the base up with a torch. You should be able to pull them out with a pair of pliers. Once you have them out just clean up the remaining ends, and flux them good. Reinsert them under heat, and then apply more solder.
They will be a little shorter, but that only requires longer flex hoses, and not a new unit. If they are too short to put back in as is then you will need to remove the threaded ends also and solder in a new piece of copper tubing. This is available at most hardware stores, and hobby shops that sell R/C airplanes.