I just did mine a couple weeks ago. The clips holding the rubber in place were super rusted, so I soaked them in rust converter after a quick wire wheel. While they soaked I made sure to clean out the channels the rubber slides into. To the point of using a tooth brush. One side slid right in the no problem. The other required patience and some Sill Glyde. Installing it could be equated to trying to pull a sticker off nice and slow to keep it in one piece and not leave behind residue, but in reverse.
Ryan