The sliders are actually easier to remove once you've seen it done. There is less work involved and you don't require a second person to hold the door.
The fender does not need to be removed. Use a forked pry bar and a brass hammer to knock the pins loose. The bottom pin goes up and the top pin comes down. There are thin retainer washers on the end of each pin called mexican hats that should also be replaced when you put the door back on. Let me know if you have any trouble or damage either the pins or the washers. I can send you replacements if you need them.