I just did mine about a month or two ago.
My White Explorer Gages came out of an Auto, and i swapped it into my Manual ranger.
There is just a rectangular unit that has the (3, 2, D, R, P) on it, and it has a shift cable, they easily slide right off the gauge cluster.
Then i took the black one off my manual (solid black piece) and put it in place where the Automatic one was located. Looks great, very easy swap.
Just found some pictures on the computer from when i did mine
Side by Side Comparrison - Notice the Auto Display and Manual Display are removed.
This is the Explorer Swapped in with the manual piece reinserted.
So you should be able to put a piece of plastic or anything inside the "hole" to fill it with white or black or whatever color you see fit.
Hope this helps