It would be nice to have a guide with pictures, any chance you could make that happen?
Here is a walk through that is from a Blazer, not quite the same, but close enough.
The cluster is constructed from 3 pieces which are held together with clips. Remove the front clear cover by unfastening the clips.
Turn each needle counter-clockwise until it stops as shown below and then mark off the location on the tape with a pen. If you do this, you should have no issues with calibration when you reassemble.
Once you have your positions marked, turn each needle counter-clockwise until it breaks free from the shaft. Then use a fork to pry each needle off. It will take a little force, but just be slow.
Unfasten the remaining clips that hold the back cluster cover in place and remove. You will then be able to pull the circuit board
Notice the 6 stepper motors, each about the size of a quarter.
(Replace stepper motor)
On the reverse side of the circuit board you will need to desolder the 4 points that are holding the motor on. These are easy to determine as they stick up a bit more.
Heat the solder and use a solder-sucker to remove the solder. If you don't have a solder-sucker, you can have an extra hand pry at the motor from the other side as you heat.
**Just be careful not to heat things up too much as this is a circuit board and you can harm other components if not careful.
I was replacing my speedometer motor, so I desoldered the following points.
Once the old motor is off, make sure the holes are clear of solder and put your new motor in.
Resolder your 4 points and place the circuit board on the back cover. Fasten the overlay piece back on now.
Now press each needle back on in the 12 o-clock position. Then turn each needle back to your mark on the tape. If you miss the mark just keep turning counter-clockwise until you come around again.
To test things out, plug the wiring harness back to the cluster. You should immediately see the needles jump down and then up to the original 'zero' points.
Make sure the needle for your new motor moved. You should really test this out first before reassembling everything to make sure your needles go back to their original points.
Typically, the gas gauge needle is a tick or so below empty. My RPM gauge was also about 100 rpm under zero at the rest position, so I made sure they were exactly in the same spot after I plugged the cluster back in.
Yours may differ slightly.
Once you determine your needles are correct, just snap the clear plastic cover back on the gauge.
Attach the cluster back to the dash and reassemble the dash in reverse order.