Can't remove thumbstick domes, they just spin. What's going on?

How to Fix an Analog Stick Drift in an Xbox One Elite Series 2 Controller
Look at Step Ten , open the 16 comments linked directly below that step, and read the comment on the first one by Matt Bolek.

There is no fix. The thumbstick dome is supposed to thread onto the part that gets soldered to the board using a very course thread. However, if you find the dome to spin, with grinding, then that means the thread snapped off inside the dome.

https://www.ebay.com/itm/126446155464

Look at the pictures and one picture has a dotted circle circling a broken thumbstick. That is what happened to you.

Unfortunately the only thing you can do is replace the entire thumbstick assembly or the controller.

So I had this problem and I got them off by using a needle nose pliers and turning them. If yall need to ask me for a video of me taking them off my gmail is

rallymarliere16@gmail.com

This problem is usually due to an attempt to aggressively unscrew the dome from the stick. The dome is held onto the stick using an adhesive (something akin to Locktite) that is supposed to keep the dome from unscrewing during normal use. Users can attempt to unscrew the dome using the longer thumbstick option available in the accessory pack. When attempting to unscrew the dome using this method, do not twist with a lot of force. If too much force is applied the stick itself may break inside the stick housing, leading to the the issue the OP is having. If the stick does not twist off fairly easily, then use a hair drier or a hot air station set to low heat (120C or lower) to warm the dome, and also loosen the adhesive. Then twist and it should release and twist off.

If the stick is damaged due to over-torquing the dome, it will need to be replaced. In that case, follow the guide available on ifixit. The part can also be acquired form ifixit or Microsoft directly.