Without the online tutorials, I'm not sure I could have got this done. I am sure that with the top upholstery on the car, I would have done it differently.
You start at the rear with glue (DAP vinyl top and trim) on the bows only. None on the listing. Even though this headliner only weighs about 1 1/4 lbs, its heavy to handle. Two of us held it in place against the glue while I stapled with the fineline.
Its important to cut reliefs in the sides of the headliner listings (template this) where they pass under the top wood or the listing will distort the headliner.
After you have it all hung, and a few staples low on the seams around the edges, you can see the problems from the inside. You can also see the unwanted variations on the topside just by looking at the stitching line.
At that point you can work from the top pulling staples and adjusting out the variations.
When you have it where you want it, get out the precut panel board arched strips and the pneumatic stapler and secure it better by stapling the panel board over the listing and taking the load off of the original listing staples.
NOW QUIT FOR THE DAY and come back tomorrow and look at it again.
Its tougher on the second day, bigger staples and drier glue, but now fine tune the installation by pulling and easing the listings.
I waited a week (adjusting several times) and then emptied the staple gun a couple times into the bows. Its got to end sometime