Get a pot you won't miss, put your pipe in it and fill with water three inches above your pipe. Put it on the stove and let it boil vigorously for 5 minutes. You'll want to move the pipe around a little to let some of the water circulate through the pipe and wash out the resin. Once your pipe is clear, take it out and lay it on a towel or stack of paper towels. Put a coffee filter in the drain of the sink and patiently pour the disgusting resin water through. Once all the water is through the filter, push all the resin to the center and roll the coffee filter around it, squeezing out the water. Voila, smokable resin, just wait until your pipe has returned to room temp. This ball of resin will spit at you unless you let it dry out for a while before smoking it, be warned.

As long as you have your pipe in the water as it heats, and don't place it on anything cold or hard when you take it out of the water, you shouldn't have to worry about it cracking.