No biggie.. you are sure that the stud is spinning and not just the head nut not stripped ? If so..
Remove the valve cover ( to slip it off while engine is in the chassis, remove clutch slave cylinder bolts and move the slave cylinder aside to allow valve cover clearance during c/c removal)
Remove the inspection plate from the lower center of the firewall
Remove the crank case timing cover through the access hole from the previous step
Remove the carburat0rs and set them aside to allow access to the timing chain tensioner
Look at the side of the cam gears, you will see markings indicating "I" and "E" depending if installed on the intake cam or exhaust cam
You want to turn the engine to top dead center on the compression stroke, rotate the engine clockwise and watch the intake cam lobe on the number one cylinder, TDC will be shortly after the intake valve closes. The cam markings should even with the outside valve cover mounting surface of the head and the crankshaft marking should be on the timing marks as viewed through the timing inspection access removed previously
Look at the markings on the camshaft holders, they are marked "1I", "1E", "2I", "2E" etc... these holders must be reinstalled after removal in the same place and direction as they are line bored straight to match the head.
Loosen the bolt on the end of the cam chain tensioner (located center of the cylinder below where the carbs were removed)
Remove the chain guide in the center of the cylinder head between the cams by removing the 4 mounting bolts
Inside the end of the tensioner, there is a slot, reach in with a flat blade screwdriver and turn it, you will feel spring tension while turning one direction, continure turning against the spring tension and hold the screwdriver once the chain is loose. Push down on the cam chain where the upper center guide between the cams was removed, lift up on the chain and slip it off the cam gears (still holding tension against the tensioner with the screwdriver)
Once the chain is removed from the gears, remove the cam chain tensioner.. another option is to simply remove the 2 bolts that mount the tensioner but I advise loosening the bolt on the end first for later cam chain install purpose.
Remove the cam holder bolts and while removing the holders, account for all guide dowels that are between the holders and head while removing (don't drop them into the bottom end of the engine)
Once they are removed, the cams can be removed to allow removal of the head, once again account for head guide dowels when the head is removed
Remove the cylinder by slipping it up and away from the pistons, as the pistons clear the cylinder, be careful not to damage them as they will flip side to side while you slip the cylinder away from the other pistons (2 will be up and 2 will be down) and also account for guide dowels between the cylinder and engine case
This will gain access to the cylinder studs for installation of a thread insert
Time Serts are the right way to repair the threads and generally come in a kit with the right size drill bit, tap and installation tool. During install into the case I will use green Loctite to hold them into place. Some techs will use JB Quick Weld to hold them from spinning but I like the green Loctite because if their is a thread issue later on again, they can be removed by heating the engine case
Let me know if you are this far and need more assistance
~Gimpster~
