I was attempting to replace my thermostat adn i broke both stems to the thermostat HELP!!!!!!!!!!

The best way to get out of that is bay drilling the old bolt out ant then tap a new tread an put new bolt . and i recommend using stainless steel bolts. but check this site www.4grabit.com
this tooll may help you.

I hope this help you :)

That's because of corrosion. It happens!

The broken studs have to be cut, or ground down flush, with the thermostat housing. Then a center punch is used to make a deep dimple, in the center of the broken stud.

Next use a small drill bit to make a pilot hole.
Two times smaller than the stud. (Bolt)
Use caution, as you don't want the drill bit to walk off to one side. Keep the drill level, and vertical.

Now come back with a larger drill bit, but one that is smaller than the stud/bolt, and will stay away from the threads. Try to drill at least one-half inch in depth. Use an Easy Out, bolt extractor.

If it feels as though the Easy Out bolt extractor, is being forced too much, and you think there is a possibility of it breaking, STOP!
Use a drill bit that is large enough, to drill a hole that will not touch the threads. Then work a small chisel along the outside edges of the bolt 'Shell', and work that thin shell to the inside. Use a pair of needle nose pliers to try to extract the shell out. One piece at a time.

(After you have drilled the center of a stud, or bolt, out to where the threads are, there is a thin metal shell left behind)