The doubler was removed and dimpled per the instructions.
The holes in the upper skin were dimpled for flush rivets.
Dimple nut plate mounting ears.
Install countersunk nut plates per instructions, 16x, using p-squeezer.
Install doubler in upper fuselage skin using standard techniques. A thin layer of Permatex #3 was applied to the doubler and skin prior to riveting to proved a water tight seal.
The top skin has a minor curve in it so the access panel was gently formed to this approximate shape.
The access panel was installed temporarily using 4 screws.
I'm very happy with the results and will install the second panel tomorrow.