I installed that same kit on my car a couple of years ago.
I removed the outer door skin, which you almost have to in order to reach the bolts that attach the hinges to the door.
Also, the front fenders.
It`s not too bad. I did the second door quite a bit faster than the first.
You basically shim the door up with it closed to keep,it in place.
I shimmed the bottom, used the strike to hold the rear of the door in place and taped the top in.
Then you just remove the stock hinges and replace with the verticle hinges.
There are about 3 adjustments that have to be made to make it swing right and to hang right.
You have to notch the inner part of the front fender to clear the gas strut.
You also have to cut the belt moulding at an angle to clear when the door is opened.
I liked mine, popular draw at shows.
You can open the door enough to get out wihout raising it, which is usually what I did unless at a show.
To me the door was a little heavy to open and close when sitting in the car. Not much leverage.
The hinges are really stout and I found the doors really didn`t sway or flex much all through the operating range.
Here is one of the threads about these.
//www.fiero.nl/forum/Forum1/HTML/096630.html[This message has been edited by TXGOOD (edited 09-29-2020).]