I have used the m10 tool to strip the bolt (while still in the receiver) in my m1a and did so as follows..
Make sure the rifle is unloaded!! (duh
he2. thread a section of cleaning rod into the middle of the tool
3. while applying slight forward pressure on the oprod handle and bolt, rotate the tool up (counterclockwise if the muzzle is pointed away from you)
4. pay attention because your extractor should jump out as you do this.
You can now remove the spring and plunger from the bolt. Take care of the firing pin as it will slide from the back of the bolt into the trigger assy. or reciever. That was the easy part, the hard part is to put it back together. In my m1a i just use .30-06 brass to compress the springs and pop the extractor back in while making sure the firing pin is where its supposed to be. Someone may know a an easier re-assymbly method for the garand