i guess it all depends on what style of bikini you have....does it have a drill type header or a clamp in header or a bolt in clamp header?
the drill style header has a thin strip (sometimes two) that goes across the length of the windshield. the sunvisor and footman loop will locate that bar for you. then you just mark and drill the holes. the front of the bikini will have a tube-like deal on it that slides in the channel on the header. do the straps in the back and you're good to go.
the clamp on header looks and functions exactly like the header on your soft top (if you have one). just line up the header and clamp the clamps down. then do the straps in the back and you're set.
the bolt on clamp style is similar to the factory soft top header, but instead of using a two part clamp, it is one part clamp and one part bolt. you insert the clamp part into the windshield slot and then tighten the bolt to hold it in place. then do the straps in the back.
i have/have had all three styles. the factory soft top style clamp on header is the fastest. it works just like the factory soft top in that regard. this is the style i currently have.
my current TJ came with the bolt on clamp and it was quite a PITA. it's just more work than should be done on something that is supposed to be very quick and simple. i got rid of this style ASAP.
i had the drill style header for my 02 TJ. once the header was installed (took all of 5 minutes) the top is a snap to put on by just sliding it through the channel. the nice thing is the header is always attached so you can roll/fold up the bikini top canvas and store it in the jeep just in case there was a sudden change in weather and you didn't have a top on or available..at least you have the bikini.
i just realized that was way more, and not at all what you were asking for, but it may enlighten someone.