Another adhesive that works very well is called Weld-On. I'm sure you would have pro-seal on hand rather than this stuff but just in case...
it's the same stuff Van's recommends to glue in the windows on the -10.
One thing I did was drilled and clecoe'd it to hold it while the glue was curing. But if I were to do it again, I'd probably just use some duct tape to hold it. That way you don't have to fill the holes in the skin.