On my way to pulling the heads on a 2001 DII and ran into a problem. The front left air conditioner compressor hold down bolt has a rounded head from previous work done by others. Anybody run into this and find a solution. The bolt is 10mm and about 4" long. Tried vice grips and also tried a 3/8" socket but it won't budge. Thanks. Tom

 

Sears sells a set of special sockets just for that purpose, the problem I've found with them is they need a good amount of clearance around them to work.
I've had good luck with driving a 6 point impact socket of a smaller size over the rounded head and hitting it with an impact gun , if you have one.

 

Scratch that problem. Soaked the thing in penetrating oil and waited. Came out with some vice grips. Will have to replace that puppy.