ORIGINAL: stikpilot
I was also advised to put grease around the glow plug hole to pick up most of the tread shaving when doing the job.
I'd say remove the jug... it's only 4 screws, and you'll be 100% sure no chips end up ruining your engine... If something was left in the cilinder there's a good chance you would have to go shopping for a new cilinder after all...