[TR] removing a broken bolt

[Brian]

Here's a method I have had good success with removing broken bolts or 
rounded out Phillips screw heads. Cut a relatively deep slot across the 
surface of the bolt or screw. Exposed surfaces can be cut with a hack 
saw or the blade of a thin cutting blade on an angle grinder. For 
recessed surfaces, I've used a Dremel tool with a small tip to reach 
down the hole and cut the slot. This can be tricky, and may require 
trying different tips for various situations. Forntunately, there is a 
multitude of tips and cutting attachments made for these tools. Then use 
an appropriate sized flat head screwdriver to turn it out. if you can't 
turn it with a regular screwdriver, try one of the screwdriver tips that 
can be used with a ratchet.Use this method in conjunction with the other 
suggestions of wax, heating, cooling, etc.