At least they're not square edged letters but it's a pain.
Warm up your roll of trim so you aren't fighting it in the least and just work your way around the letter. I once cut some 2x4 blocks from a few to several inches long and sized in depth to fit the space between bench and the lowermost lip of the new trim. You only need maybe 8 of these to complete that letter you are working on in the pic.
A few long drywall screws, strategically placed where there are no blocks in the way. can help too. The long screws dont have threads the whole length so the smooth shaft would be against your trim.
Use the wide trim, glue it well, don't move it untill it is set good, work in a warm area.