I don't think I really need to explain what this does, but in short its a speed adjustment as to how long before the wipers next wipe the windscreen in intermittent mode.
For those looking for one there are a Left and a Right wiper stalk. Make sure you get the correct one because as far as I'm aware the left wiper stalk was only fitted to RX-8s that went to Japan and Australia, every other country had the wiper stalk on the right side.
Here is a pic of both wipers stalks
What is required?
RX-8 Wiper Stalk
Phillips Head Screwdriver
Some Masking Tape
Step 1: Remove the 3 screws circled in red
Step 2: Loosen the steering height adjustment allowing the steering wheel to freely move up and down
Step 3: Split the cover in half (top and bottom)
Step 4: Remove the two screws circled in red and unplug the wire circled in blue
This should loosen the wiper stalk and you should be able to slide it out
I highly recommend putting a few layers of masking tape as pictured because it is a very tight squeeze to get the wiper stalk out and won't be any easier putting the new one in
You could probably undo a few more things (not sure what) and it would probably make it a lot easier to remove and fit but I didn't have much issue doing it this way so never looked at another way of doing it.
Step 5 Slide the new wiper stalk in and repeat the steps above in reverse
End Result
