This ifixit article does work. [guide|33708]
Tried taking apart two trackpads by removing bottom bezel then the battery and heating up the trackpad from the bottom. After removing the trackpad completely, fixing the spring, then reassembling; the trackpad still would not click.
Then I tried the process in the article, using a heatgun, and it worked like a charm. As soon as you remove the thin piece of plastic that sticks to the trackpad circuit board you will be able to click again. I cleaned the trackpad plastic around the edges and reinstalled so it wasn't touching the surrounding bezel.
Just note, you are only removing the plastic cover from the trackpad circuit board, not the entire trackpad assembly like in the other process that was mentioned here.
I was skeptical at first but it did work for me!