I carefully removed my stainless drip rail moulding without bending it so I could blast and paint behind it. Now how do I re-install the trim so it will be tight on the drip rail?

If the lip isn't bent, you should be able to place it over the top and then push it along the bottom edge to install it. Start at the sail panel end. Do not entirely seat any portion of it without going along the whole length to try to keep from putting a kink in it.

This is not easy as it can be bent ever so easily. As 69X11SS states start at the sail panel. But from my experience, as you work your way to and over the doors the top must be latched over the top lip while rolling the bottom down over the mounting rib. A little at a time. Latch the top and roll down. It will appear to be way off at first but as you roll it on it will slowly conform to the mounting rib. Some crimping of the bottom edge is possible along with some liquid emblem adhesive for the stubborn areas which can be taped while it sets up. And by all means, no hammers/rubber mallots. The smallest tap no matter how tempting will most definately mean a new set. Good luck.

It can be done as the two suggested. Patience is the key!

If you must use a hammer, use a block of wood, 2X4X12-15 inches, against the rail. Best to use an open hand. Patience is the key!