ZZP has new intake gaskets for $50, so yes, it's probably worth it to remove them. Haynes manual makes it sound a bit scarier, having to detach EGR valve, alternator, drivebelt, assorted hoses and electrical connectors, etc. Is that necessary? I have found that Haynes does go a little overboard in the removal of things, if only to make access a bit easier. I figured I'd rotate the engine and work it from there. They also recommend draining the coolant. I'd guess that's only because it's likely you're gonna lose some with removal of the UIM. Maybe I'm just being paranoid.