Removing the bumper is pretty simple. Putting it back on is just as simple, but more of a pain in the ass. It's one of those 'bleh' things.
When I did my little grill experiments (failed, since gutterguard hates me and so do tinsnips ><), I re-attached the bumper with the 4 popper-bolts that attach under the hood. I then attached the sides and finally the plastic bottom plates. I would advise attaching the bottom plates before the sides, since it can be a real pain in the ass to fit correctly.
When I did my little grill experiments (failed, since gutterguard hates me and so do tinsnips ><), I re-attached the bumper with the 4 popper-bolts that attach under the hood. I then attached the sides and finally the plastic bottom plates. I would advise attaching the bottom plates before the sides, since it can be a real pain in the ass to fit correctly.