Front head shouldn't be a problem, might need to remove the radiator; it's the rear that might be a bit messy. I'd almost drop the engine though. It doesn't take that long beyond what's necessary to get to the heads.
"To strive, to seek, to find, and not to yield."
"You don't cross the mountains, they let you through."
KTM 525 XC-W // KTM 950 Adventure