What is the best way to repair/tighten a lose door jam for my shower door enclosure? It seems that the screw that holds the door jam just turns and no longer tightens up. The shower door is about 8 years old - and was originally installed by the builder. How do I remove the door so I can replace so I can replace the anchors that hold the door jams in place. And what is the best way to replace/repair the loose anchors?