Chosen Solution
So my new power flex cable came with a power button bracket already attached. Great. The problem is, I can’t get the long cable that curls around the corner off of the old power cable bracket. It doesn’t seem to be stuck on, it’s more like it’s got tiny welds or something. I also can’t get the bracket off the new power flex cable to use the old power bracket (with the long corner cable) instead. Help!
This power button flex is meant to be replaced in its entirety. While there is no specific iPhone SE guide for this repair, you can follow the iPhone 5S guide as it will be very similar.
My experience is that it is possible (but difficult) to separate the grounding strap from the old power button bracket, and then attach it to the new one through the screw hole that also holds the power button in. To remove the grounding strap from the old power button bracket, I very carefully inserted a spudger in the marked location and gently wiggled / worked it in to separate the strap from the bracket - this seems to be the area furthest from the spot welds holding them together. I think it may be possible to damage the flexible cable of the strap if too much force is applied, so wiggling the spudger gently left and right a bit at a time is probably the safest way to go rather than trying to push it straight in. When replacing the grounding strap, I tucked it behind the rubber camera bumper and tried as much as possible to ensure it is pushed along to the right and down the right side of the phone, so that it did not bulge out too much just beneath the power button bracket - the spot welds holding it to the original bracket kept it close to the bracket before, but with only the screw holding it in on the new bracket there is some potential for it to bulge out towards the microphone and camera flash just below.
