The rearmost driver's side one took a little finagling the last time I messed with mine, but on balance it really wasn't too bad and they came out and went back in OK without removing much of anything. I changed them in the parking lot of the campground before driving 300 miles back home from a camping/ wheeling trip where I'd lost an ignition coil and thought "might as well..." if that tells you anything.In spring I'll be doing this exact job, with heater T's on top. Are the spark plugs all easily accessible?