1. Pull out the needle stops
2. Take car for a drive with a friend in their car and test it out at different speeds (20, 30,40 etc) until you are getting the right speed
2a. If needles are reading too high, wind past the needle stop position (you will feel some resistance, push a little past it) and test again
2b. If too low, push in the opposite direction (go clockwise till resistance, push past)
2c. If the needle movement is slow (lagging behind actual speed then catches up) then the needles are inserted too far into the circuit, raise it a little (pull needle gently) and test again
2d. If needle does not move at all it isnt inserted far enough.
3. Continue adjusting until it reads correctly
Same goes for all the gauges(speedo, fuel, oil pressure, oil temo, tacho)
Speedo - Follow what i said above
Tacho - Go by the sound of the engine or if you remember what revs you were at in a certain gear at a certain speed (eg. In 2nd gear at 40km im at around 3k rpm). Adjust till you get it correct
Oil Pressure - Get the car up to operating temp and make it so the needle sits in the right place (hopefully you rememebr where it was positioned)
Oil Temp - Same deal as above, warm car to operating temp and get the needle to read around the middle, should be a marker on gauge face where the middle/ ideal temp is
Fuel - This one i buggered myself as it has a weird resistance to it but im too lazy to fix it Just fill the car up at a servo and get the needle to read full.
If your still having problems after this, pay someone to fix it.