How do these parts come off???

Trim removal can be very frustrating for anyone, novice or not. It really helps a lot it if you know what the clips look like and understand how they hold the trim in place.
The front and back window trim clips need to be pulled away slightly from the trim to release it. Slide the tool tip all the way under the trim and along it until you feel the pointed tip contact the clip. Gently hook the tip behind the clip and pull towards the middle of the window to release. Doesnt have to move much, 1/8" or less, to release the trim from the clip. Some clips may break but its much cheaper and better than damaging the trim.

There is a single screw on the rear upper end of the 1/4 window trim, the rest is just bent wire spring clips that will pop out when the trim is gently pried upwards. Use a wide stiff putty knife or similar.

The screws on the gas cap are "tamper proof" or "one way" screws, they supposedly kept the cap from being stolen. I have always been able to remove them with a strong pair of pliers or vicegrips.