basically follow this up to the point the cluster is out from the dash, then unscrew the bulbs from the back. It's not required to take off the plastic cover. Size of leds is 194/74
Question though, how many light bulbs will I need?
Theres 3 different types on the back side i took my gauge cluster out yesterday because my lights are burnt out for temp and fuel. Theres 2.big size ones for rpm and spedo and the rest are tiny only difference is the plastic is brown on a few and black on a few and im not sure why. I called mazda and they had no idea either so ill be waiting tell monday and see what they have to say. I think theres about 10 little bulbs
If you don't want to replace the lights with LEDs then you can get regular bulbs from any auto parts store. I believe the sizes are #74 and #194 but I don't remember exactly. Replacing the bulb locations with LEDs will give you hot spots across you cluster and looks like trash. If you want LEDs you will need to spend some time installing them in other spots
I dont know what the big fus is. Just pull the outside cover, unscrew the cluster, unhook the connectors pull the desired light out and replace with bulb listed above. Took me no more than 5 min.
Takes no skill even the guys that aren't mechanically incline can do it.