I Didnt make this.. Although I did do it to mine.. I didnt use these instructions however I did do the same..
How to Install LED lights in your Mustang Gauge Cluster
1. Remove Gauge Pod And Headlight Knob [ 2mm Align Wrench ]
2. Turn Ingition on and take picture of all levels [ Fuel/Batt/temp ]
3. Save that picture !
4. Use Torx-Bits to remove Cluster [ T-15 ]
5. Pull Out Cluster and Remove Bottom First
6. Disconnect 2 Connections [ Kinda a Pain ]
7. Once you have cluster remove the back plastic peice to get to bulbs
8. There are 5 Bulbs across board of cluster
9. Use needle nose pliers and carefully twist the white bulb sockets to the left and pull out
WAIT WAIT WAIT- If you have black face cluster Make sure you peel off black face gauges with a flat head screw driver and your going to have to sand down the complete inside of the plastic guage face. I used 1000 Grid Sand Paper. The Purpose is to sand down the Green Tint that makes your factory light look green, A good way to make sure the Green tint is all gone is too sand it down and point it up to the sun or light and you should see if the green tint is gone. You will definintely see if its clear or green. MAKE SURE you sand all of it ! You can leave the turn signals and High beam symbol alone..
10. In my opinion the hardest part is pulling out the bulbs because they will break and you will have to take peice by peice out, but if your lucky they will just slide out
11. Once you removed all bulbs and replaced them with LEDS [ Make sure white sockets snap into board . Put cluster back in and plug in the 2 connectors and MAKE SURE they all light up..
IF some do not light up simply check with ones they are and simply take the bulb out and insert it the other way, until it lights up
12. Okay once all the bulbs light up.. your needles are going to be everywere and your going to go holy crap what do I do? .. Take a look at the picture you took in the start and pull out needles , and put them in the direction they go.
And just reverse and install everything
This is how mine looks like