I've found the trick to easily folding up a wire crate is to open the door, and take that end down first. Opening the door seems to give that panel a bit more flexibility, making it easier to disengage. After that panel is down, do the back panel, and fold the crate up. Also, the heavier gage the wire is, the harder the crate is to break down.
I have Midwest crates, a pretty dominant US wire crates brand. They are easy enough to fold and unfold regardless of size, but the larger crates are kinda hard to carry without pinching your finger and are not all that lightweight.
But for occassional fold down and transport even the 42 inch is reasonably managable for one person to fold and load in a car trunk for example.
I never found a need to open the door but it does help to fold that side first.
Oh, you have a drop pin crate. Yeah, they can be a real pain, but the older ones were built like a tank, with heavy gauge wire, and because of the corner rods, are very hard for a dog to get out of (not saying it can't be done, but it's pretty darned hard). My Midwest Metals drop pin crate is about 25 years old, and other than the metal pan rusting through where the water bowls have sat over the years, is still in good shape, and gets used every day.
If you want one that is easier to take down and put up, you need a folding crate. Then you do what I described above.