The only way is to pull the head off enough to get it back in that slot, I forgot about that once. I wouldn't risk bending it, just pull the head and set a new head gasket on it, get it done right and prevent the issues. It's going to be a real bitch to get that sprocket off with that guide in the way, you might have to pry it for a while with a small flat head screwdriver. Be careful to not damage the cam chain while doing so, otherwise you're gonna have to do even more work and rehone the cylinder.
