I have a 2019 Quick-E. The electronic part of my rear light (lens & light) fell off recently. The light is made by Spanninga, model 'Vena'. It is screwed to the fender. I bought another, the same model, and replacing it was a bit of a pain 'cause of small mistakes I made..... It should be pretty easy though, if you do it right....
The fender has 2 parts- an outer plastic part, and an inner metal frame. Both are bolted to the rack/frame. The wire for the rear light runs loosely through a 'track' on the inner metal part 'til it reaches the light.
You will have to figure out how to attach the PDW fender to the bike, and how to route the wire safely. Maybe you can still use the metal frame?? Certainly some drilling is required....
1) unbolt the light and yank it off the fender, leaving the bare wires. really- just yank it off. The wires ( grey & white) are very thin braided 22g, but there's a couple extra inches in the fender.
2) Pry open the Vena light from the bottom so you have the separate clear lens and the black housing. In the housing is a tiny 2-hole plastic insert to attach the wires, marked +/- on the back of the housing. (FYI- the light is a 6V "dynamo' version and the pos/neg wiring does'nt matter when you re-wire it....) The insert may look like part of the housing, but from the inside you can detach it from the housing by inserting a small nail/probe into the center hole and pushing it out. ( I know this sounds weird, but believe me it will make the whole reattachment easier & sorry I don't have more pictures).
3) Assemble the fender / metal frame / wiring to the bike as you see fit. Leave enough wire exposed at the back to attach the light, about an inch? Clean up the ends. You'll need about 1/2-3/4" of bare wire to connect the light.
4) poke the bare wires into the insert, then replace it into the housing. (This is where I screwed up, as I didnt strip enough wire to make a good connection and the insert was hard to remove once installed into the housing).
5) Lightly put the lens on the housing & check that it works. First bolt the housing onto the fender, and then snap the lens on completely. I taped the the lens to the housing 'cuz I didn't want it to fall off again....
Good luck! BTW I have PDW metal fenders on my other road bike and they are awesome!