So about 15 months ago I bought a road bike (aluminium frame) with a threaded bottom bracket (Shimano BB-RS500) and while they were setting up the bike at the shop, they realised the bottom bracket was put on reverse sided (left cup on right side and vice versa), then they removed it and installed it the correct way (right cup on right and left cup on left side). I asked them if that would be a problem and they said it would not. This was about 15 months ago.

Two weeks I took my bike to get serviced and I mentioned a clicking sound from bb to my mechanic (different shop and mechanic) he said he will take a look at it. When I picked up my bike, he said the right cup was way too tight to remove. So that initial reverse installation was already bothering me from day one and since I heard this tightness it started to bother me even more.

My question is if I manage to uninstall that bottom bracket, what damage may be beneath it, like would the threads on the bb be damaged or the threads in my frame would be damaged, and would replacing that initially reverse installed then correctly installed bottom bracket solve all possible problems (including that clicking sound)? What would you suggest me to do? Should I just leave it as it is or should I replace the bottom bracket (I wanted to upgrade my bb too because it came as a lower model than what was written on the product page, I'm a little perfectionist).

Thanks for your help in advance.