This is a very easy procedure and the adhesives to use will be Duramix 60 min or the Fuzor 60min working time cartages, 3M has one but its a three layer process and a waste of time and money so don't use it. I always do full panels to the factory edge so not quit sure what you mean by wanting to flange.
I have done it three ways, with the screws like you were told or with big C clamps and on the 69 gto trunk pan I used my weights to hold down. (Find that in a body shop manual)
Its a simple as grinding a two inch strip on the edge of the panel to be bonded and a two inch strip on the car that it gets bonded to. (Fit and refit many-times first) Shoot a bead on both the new panel about a 1/4 inch dia and same on the car. With a spreader spread out to cover all your 2 inch strip so waterproof and fit panel in and clamp down tight like you were going to weld.
The fuzor has fine beads in there so you can't over-tighten and Duramix does not need beads as 1mil of product is all that required.
Once clamped down any excess, wipe off or spread as a seam sealer.