Great guide! Here’s my variation of a trackpad clicking problem and my non-invasive fix. I noticed a little round silicone thing on my desk at the same time that clicking no longer worked. I realized that this was the silicone pusher thing that had got hung up on my desk surface and was pulled out from its hole in the track pad bottom. My fix consisted of working the thin edges of the silicone pusher back under the plastic bottom plate with a flat edged eyeglass screw driver gently pushing it under the bottom plate around the circumference of its hole. By pushing gently and in small increments (to avoid slicing the edge) the thin edge of the silicone pusher got worked back into position under the bottom plate. It took a combination of (gently!) pushing the edges and wiggling the silicone pusher to get it into a position wherein clicking steadily improved until it was like new. I know the pushers are positioned right because they wiggle loosely in their holes.
I would also add that during the reassembly process, make sure the drive stays firmly seated in the grommets. There's a tendency for it to come out or partially out. I kept nudging on it to make sure it was fully seated. Then the antenna screws line up nicely. Some of the problems I read about getting the screws in I suspect arise form the hard drive not being fully seated.
I decided that there was a greater risk of breaking something by not removing the logic board than by removing it. The old hard drive comes out easily enough, but the new one would just not quite go in for me. Lining the screws on the outside of the new hard drive with the rubber grommets is so much easier with the logic board out. I used masking tape with pencil marks on the case and on the drive in order to line up the screws and the grommets with the case right side up. IMHO, by the time the antenna is off, removing the logic board is relatively easy.