can you unscrew the recon cab lights and re apply RTV stuff. I am getting a little leak, but I am worried about not being able to screw them back in and getting a tight seal.

Any pointers would be great!

OE

 

I don't see why not. I've never had to do mine, but take self tappers out of sheet metal and put them back in all the time. If you have any doubt, go to a screw that's just a hair larger.
BTW, I used clear silicone on mine and then hit the screws on the lenses with clear nail polish. Been on since '06 and no leaks yet, knock on wood...

 

This shouldn't be an issue. Remove the old screws and clean ALL of the rtv off. Use some denatured alcohol to make sure there is no oil/grease/wax on any of the mating surfaces before you reseal the base. And try to squirt enough on the screw holes so that it actually leaks through the hole a bit. Do the same thing with the hole for the wires. You really can't use too much silicone on this. Just be sure to clean any squeezed out excess off before it dries.