I just happened to pull my dead one out yesterday. Hardest part was getting the tiny 2 screws out since I didnt have correct tool. Ended up using a file edge on a fingernail clipper, worked great. Had it out of car in under 20 minutes. (I ended up dismounting/ moving aside light switch for better access)

You might have to turn/ angle/ slightly manipulate position of the gauge as you remove/ install cause the painted metal plate doesn't go perfectly in or out through hole in back of speedo cluster.

Make sure you unscrew correct screws, it's the outer ones at edge, not the 2 directly next to the capillary tube.

Make sure you drain some of the coolant out of the block, or it will flow out when you unscrew the sendor. And don't forget to put coolant or water back in; I turn car on, put heater control on full/ fan on high, and over the next 3 or 4 minutes, pour in the fluid, until it is at proper level.

Oh, and for goodness sakes, be careful with the tube, don't bend it too much!

I put a bit of that white superduper thin (plumber?) tape around the threads of sendor when I screw it back in, I'm not sure if that's needed, but I do it anyways.

I'm looking for another temp gauge myself, best price I found is $180. Can I ask where you got yours? Repair of gauge is a bit cheaper, but after postage it all comes out the same.