I've only done four string jobs (for myself), The first two were an adventure, but it did get easier with each attempt. Yesterday I decided it was time to try replacing the grommets and bumper on my very used POG 90. I read what I could, and watched YULitle so was forewarned that it may be somewhat frustrating along the way. The old set was really beat. Crack in the bumper and many split ends of grommets. This made removal a little slow as some grommets had to be coaxed out with the blunt awl. I wasn't worried about the frame, as this racket already has the paint worn off most of the upper hoop, but I was still careful so as not to damage the head. I had to pry sections of the bumper on both sides of the crack to finally release it. I briefly thought about soaking the new set in warm water to make it more pliable, but instead just jumped in to see if maybe I could get lucky. The only real resistance I got was the throat piece. It just did not want to sit all the way in. I left that thinking the strings would pull them tight enough and went on to the two side pieces. A little slow in one or two spots, but no problems. Now on to the bumper. It started fine and was moving along until I got to the other end, and then the first end started lifting out. I had to go back and press harder, but that didn't seem to help so I pulled the whole piece out and started again. This time it seemed to sit right, and toward the other end I suddenly heard a "snap" sound and magically the bumper sat flush to the frame and all I had to do was push the last two grommets in and I was done. I read where MRT's are supposed to be able to change out a grommet set in fifteen minutes to pass their testing. I can't say for sure, but even with all the retries and taking my extreme time, I was able to accomplish this in a half hour or so. Is this typical or was I just lucky, and is it normally much more of a hassle? BTW I strung up the racket as a one piece 14x18 and it's fine as can be. Now I'm wondering if I should put some guard tape over the new set to make it last. Opinions?