I have tried this more than 10 times with my bowl and friends bowls as well. I have a pot dedicated to this as well as the utinsils that are needed and with this way you get to keep the resin to smoke in the future.
Fist find a pot that you will never use for anything else because after this you wont be able to.
Fill it up with water about 3" above your glass bowl.
Bring the water to a boil with the pipe in the water. this way it gets used to the heat!
Find a plastic spoon that you will never use for anything else again as you will not be able to with this either.
You will have to watch this closely and keep stirring while the water comes to a boil. DO NOT LET THE BOWL JUST SIT ON THE BOTTOM FOR TOO LONG. This will cause cracking in the glass so keep stirring (be gentle though). let the water boil for 15 minutes while you stir.
Once to a boil you should start to see the resin float to the top of the water. This will look almost like black oil at this point.
While strirring your bowl around take time to scrape the edges of the pot to loosen built on resin. this will cause it to move to the center of the pot.
After about 20 minutes scoop your bowl out of the water and hold it with a pot holder and drain it out above the pot. Then place it back in and continue stirring.
You will pull the pipe out one more time and drain again after about 10 more minutes have passed since the last pull.
After this last drain set you bowl off to the side on a towel and let cool at room temp.
Take your spoon and scoop the resin that is building up in the middle of the pot and scrap off on to a hard surface. Then scrape the rim of the pot again and pull out the rest of the resin that has built up.
Place the resin in a cool spot being sure to form it for your your bowl, Genrally I just roll it up in to a circle, but this must be done while it is still hot so have your hands ready.
Drain the water in the pot and clean with a scrubber that you will never use again. You will not get all of the resin oil off of anything you use here but you can clean it!
put this stuff in a box once clean and use for later use.
*NOTE: This will stink up your whole house when you do it!
I hope this helps. I do it every time I have to clean and it works verry well and you get to keep the resin.
Just never let your bowl sit on the bottom you MUST have constant movement!