how do you swap the millage tumblers? is it even possible?

I doubt it, better to replace the entire cluster. can always find them on Ebay cheap.

Yes its possible. I did it before on my old car when I swapped a cluster that comes with a tach.

yea, it is possible. at first when i tried to get the tumbler off the cluster (with the tach) i couldnt seem to get access to it. it was like the guage part was glued down and i was afraid i was gonna break it. then when i took my cluster out of my car and tried it, it just poped apart. it took a lil more time to get the guages separate from the base but i got them and then the tumbler is just held on by 2 bits (same as the rest that hold the cluster together)