Get this tool:
From this guy:
Tim Oelerich 262 388 2509.
Don't waste time with screw clamp type or anything else. Pay his price and don't cut corners---it makes the job cake. I did mine with intake off but I think you can get the leverage with a breaker bar in the drive hole like I did. Ask Tim. Use air line in the plug holes, not rope.
Here's the vitons you want; get the right stem diameter:
