The best way is to have someone young and flexible to do it for you.
There's lots of stuff in the way, including the steering column. You may need a flexible socket on a nut driver to get at the 4 nuts holding each cluster on. You'll need to remove the speedo cable, then get the clusters down below the dash where you can remove the wires and the oil pressure tube (maybe undo that one before pulling the gauge cluster out.) The light sockets pull out so do that to get those wires out of the way first.
Good luck.
