You should remove the door opening sill plate before servicing the weather strip for the rear door body. Then, get the weather strip to pull it from the fence at the door opening. For installation, place the color dot on the weather strip at the top of the B-pillar, slide it onto the fence at the B-pillar and pull it down along the B-pillar. After that, connect the weather strip along the header and down the C-pillar and once more along the sill, making sure any loose material is moved toward the front of the opening. Afterward, reattach the door opening sill plate and test that the weather strip completely seals.