Yup, you can use a gas grill and do it outside also. Crank it up on high and let it warm up, put cylinder in for 10-15 min. I would remove one dome from your head and put it on the good sleeve, and use a piece of scrap steel to span over it and drill two holes so you can bolt it on each side to clamp the sleeve in place so the good one doesn't move. After it's been in there for a bit, pull it out using welding gloves or similar, flip cylinder upside down on the bench onto some wooden blocks and the sleeve should slide right out. You'll want to clean the cylinder inside mating surfaces and check for damage.
You probably want to port your new sleeve most of the way before it is installed...and check deck heights as well. Then put sleeve in freezer and heat cylinder. You have a bit of working time this way. Drop the sleeve in and line up ports quickly, then clamp a head or something down to ensure it stays put. You will need to check that the sleeve doesn't protrude from the cylinder, you will probably need to deck the top. Then finish porting and get it bored, good to go!
Best of luck!
