I'm not familiar with the particular bar you're talking about. But design should be similar if it is a competent/fitting bar. I've installed three now, as well as my full cage. My first took a little over three hours.
Remove all of the rear carpet with the soft top up (closed) to access all of the plastic clips, then take a look at the metal tray. This alone will give you alot of insight.
Remove the forward most portion of the parcel tray. It's held on by like 15 bolts. A 10mm socket and ratchet will make quick work of it. Image below:
You will expose it and see basically what's above. Also, after your carpet is out you can lower your soft top to make it less cramped.
Then have someone help you and set the bar in place to see how much you have to cut from:
Blue shows actual space that you generally have to clearance.
After that, cut! Then the bar will sit in place (you'll probably have to remove your plastic covers for the seatbelts as well as the the seatbelts themselves. Bars usually use the large seatbelt retractor bolt as a mount.
Once it's in place, sit back and take a look. Have a beer, and make sure it's all straight looking, because the next part is the most frustrating/permanent.
Drill. You can either mark the holes with a sharpie, then pull the bar and drill, or just drill through the holes. I'd recommend using a small pilot bit, and finding a 90 degree drill because the clearance is miniscule.
Once you have your holes, get the car up on stands in the rear and remove the fender liners. You'll see clearly what you've got to do. At this stage I took a dremel and rounded the holes out, maybe you've got them perfect, whatever. F U. Put the bolts through, backing plates, nuts, and crank the shit out of it.
Do the same for the front mounts (these one's are very accessible and easy.) Drill, bolt, backing plate, nuts, a friend, ect.
Wallah! all that's left is cutting that sheet metal tray you removed (with all of the little bolts) to fit around the new bars protruding from your car. But don't fret, it's worth it.
Then install carpet, stand back, and fap.
I hope that was somewhat clear. I wish I had pictures, considering how many I've done now. I can tear my car down sometime if it would be really helpful, but this was the best description I could muster. It's not the worst thing in the world, just one of them