im right in the middle of swapping in a celica 130mph speedo right now, and its really easy
all you need is a #2 phillips screwdriver and a box that can fit the instrument cluster inside... as you remove each screw, you push it through the top of the box, in its approximate position, just like a pin cushion.
in fact, i call it the screwcushion, and yes, its patented
im also going to get the panel scanned, and hopefully get the image colors reversed, so i can see how white faced gauges look.
theoretically, it should be as simple as scanning it, PSP7ing it, and printing, but i imagine something will crop up.