I reached up from underneath. You will have a good amount of you arm up there, but it will work. Like Maryland Bandit said, it has a self tapping(?) speed nut that cuts it's own thread when you install a new one.
Old, red (and worn) crest:
Crest off the car:
New, gold crest. NOS part from one of my TAC buddies:
Here is all three that I have, Left-original, middle-off a parts car that I have had installed for years, and right-the new NOD gold crest:
Very easy to R&R (remove and replace).