well I really don't have any more pics at this time because the trucks in AZ and I am in CA. here's a breakdown on what you need to do,
the cut out in the cap/camper must fit the back window exactly. not close, but exactly.
the lip the accordion boot attaches to should be appox. 1/8 inch. thick. this gives the boot something to bite on.
if your cap/camper is already cutout in the front and it doesn't match the window exactly. you must make it match. I find the easiest way to do this is to add 1/8 inch aluminum bar or sheet to the cap. then cut to match your window opening.
to match the opening the cap must be fully installed on the truck. then scribe the opening. to cut I find it easiest to remove the cap.
once you have both openings matching reinstall the cap. start installing the boot in the middle of the bottom of the opening. working your way around. I find that on the corners(especially on a 4x4) is to glue the corners on the cab and cap. this keeps the boot in place when the body flexes. I use black 3M weather-strip adhesive. make sure the boot gets a good bite on both surfaces.
go all the way around. when you get to the end don't just butt the 2 ends together. cut a splice from left over boot and glue the 2 pieces together. I like a 4 inch splice on each end so 8 inches overall. this makes for basically an air/watertight seal.
I also like to use a protector on the bottom of the boot. I use Cordura with a foam insert. this protects the boot from abrasion whenmoving stuff in and out. this step requires sewing.
any questions and I will try my best to help.
oh yeah, links to boots,
http://uni-grip.com/products/accordion-seals
https://www.all-rite.com/catalogsearch/result/?q=accordian
http://www.fixmyambulance.com/product-p/uni-ed5389.htm
many more just search
highdesertranger