It's not a massive problem to resit needles, just a bit of patience and some manual skill. To take them off use 2 spoons for even leverage underneath needle and they will pop out, just be careful not to bend anything Fuel gauge is easy one, fill car up to max and put it back pointing to Full mark. Speedo is a bit more tricky, I was using GPS to keep steady 40 or 50 mph (depends how comfy you feel) and just pop it in pointing to GPS value shown. RPM is as just easy, warm up the car and once it's idling at 650, put the needle in.
If odometer is counting in km it means that either wiring on a back bypassing it or your converter is not working as it should.