Can’t pull those off, you’ll bend them. As Moonraker wrote you lever them out if the groove and push off the front.
I’ve been trying. I’ve tried with a pick & lock set, needle-nosed pliers… adjustable wrenches… Nothing’s moving the c-clip. So, I’ve deprioritised it for the moment.
I had a pause in work (or, at least, doing a couple of hours on Alien Poker each day) due to the big A word, i.e. adenomyosis. It’s luckily not fatal, but it’s not wildly pleasant either.
Anyway, I’ve done a bit of work on stripping down the cab with lots of stoppages due to a lack of suitable knowledge and equipment.
I’ve been putting my tumbler on for too little time (apparently, it should be minimum 4-8 hours with
24 hours being more typical). I had wondered why dipping everything in Autosol hadn’t seemed to help!
Then I realised that the pin was absolutely filthy. The picture underestimates just how utterly dirty it is. Every piece of metal and section of wiring harness is a total grimefest (and not the
funkily-attired artist who formerly dated Elon Musk, either). So, I had to research how to actually clean stuff without resorting to a toothbrush and washing up liquid, and now have a 9L Labbasics ultrasonic cleaner plus automotive degreasing fluid coming from Amazon.co.uk. Research on Pinside suggests you need at least a 9L cleaner to clean wiring harnesses, as the wire basket inside the machine holds less than the diameter of the tub.

My earthing braid is shot (I’m sure it’s not doing much grounding hanging off in little chunks, as on the far left of the image), but Pinball Mania has it in multiple ampages (10A, 15A, 30A) and I’m currently not sure what ampage I need. I checked the Alien Poker manual (which is useless) and the Williams Flipper Solid State Maintenance Manual (which is only slightly better), and neither told me, so I‘ve asked here and on Pinside in the hope someone knows.

I stripped all the incandescent bulbs out of the backbox and realised I should probably - if I could, while I’m doing all this work - replace those old orange displays with something newer and funkier. Not sure if
@AlanJ does displays for Williams early SS, so I’m investigating
XPin displays as an alternative.

Finally, my replacement side rails arrived and were horribly bent in multiple places. Happily, Marco Specialities immediately fixed me up with some new (hopefully unbent) ones.

Apologies that there’s so much minutiae on this shop log. Thing is, I read a lot of shop logs and they tend to go “I stripped down, sanded and painted the entire cab” as though it happened by magic. Whereas, everything I attempt seems to involve a massive clueless faff where I have no idea what equipment or techniques to use, or how to use them, and everything takes ages and goes wrong. I’m sure I’m not *that* hopeless (just slightly hopeless), so am including every terrifying mistake, time-consuming mess and blind alley in the hope of assisting someone else who takes on a full restoration with no experience or relevant skills other than boundless optimism.