There's a good chance your headliner bows are numbered. Look at the ends of the bows for little stamped numbers. 1 is the front.

If they're not, test fit them to the car without the headliner, and switch them from place to place until you're pretty convinced that you know which fits where. Mark them, and remove them.

Next, slide the bows through the sleeves in the headliner, and then put one of the bows nearest the middle of the car into place, leaving the other bows hanging.

Orient that first bow as close to vertical, with the bow upward (like it's going to be when you're done). Don't worry if it's not perfect for now.

Do the next bow toward the front (or rear) of the car. Then do the next one aft (or forward). Alternate moving one bow forward, then one bow aft. Leave the edges loose.

Once all the bows are in place, make sure the headliner is centered, so that you have enough material to tuck into the edges. Also make sure that there's enough material to tuck into the front and rear ends.

If you're worried about wrinkles, you can warm the headliner - gently - with a hairdrier. A heat gun is probably overkill.

Finesse the bows forward and aft until the headliner is just barely taut along the middle of the roof.

Start stuffing the edges. I like to first ensure that the tail end is where I want it, then move forward along each side so that the two sides come up to the front at about the same time. As you work, take care to not pull the edges too far forward nor aft, or it'll get funny sags in it.

Light tension at the bows and a little stronger tension midway between them will help the headliner stretch nicely, giving a nice 'billow' near the edges and between the bows. If you don't do this, you can end up with sags, which look terrible.

After the back and sides are done, do the front. As you pull the headliner forward, you may find that you need to readjust the bows in order to get the nice puffy billowy appearance the thing had when it was new. Too much tension leaves you with flat sections of headliner between the bows, too little leaves sags. You might end up doing the front and rear a couple times each as you look for the 'perfect' tension/bow placement.

Finally, once it looks like eveything is in the right place, go back along the sides and give them their final stuff-into-the-serrated-brackets. This is when you can give a little more or a little less tension to the headliner so that you get a nice taut install. Don't tug too hard or the serrations can tear it.

Finally, feel around in the front for the dome light mount and cut a SMALL slit right in the middle. You want a hole that's just big enough for the wires to pass through. Wire the dome light, then feel around for the mounting holes, and mount it. Same with the visors - feel for the larger hole(s), poke a hole in the 'liner just big enough to fit them into place, then find the mounting holes and twist the screws into place. I use a dental pick for this.

If that doesn't work, bring it over here and I'll be happy to do it. Not for free, though.

Best,

Cameron
Rose City