I've done a number of 8100's but never had to open the one 9100 I worked with--some 20 years ago! Now that you've downloaded all the 9100 manuals from the Orban FTP site, you can verify or discount some of my suggestions. I would suspect your company will be happy after you are finished, because the parts budget will be less than $50.
Based on the 8100's, some suggestions:
Tools needed: 25 watt soldering iron, side cutters, needle nose, good straight blade screwdriver, fresh roll of solder wick or Radio Shack equivalent, and two coffee cups (see below).
Do the power supply cap replacements first, as this will take the most time. Especially if you are doing this overnight because you don't have any back-up processing. If you run late, you can always do the caps on the cards another day.
Getting to the power supply components requires patience--and one coffee cup for all the screws, since you will need to remove the top and back panels! Suspect you will find the big electrolytics are something like 5000 uv/@50 volt computer grade caps. If the 9100 is like the 8100 they are held in by springy clamps, so try to find the same size (diameter).
On the 8100 there is a little board with the regulator IC's attached (these are the ones you see on the back that look like power transistors). You need to pop these out, carefully bend back the back panel, & pop the circuit board off it's plastic stand-offs to get at the two 47 @ 50 volt caps. I've replaced these two ways--either pull all the wires off the boards to get the board out into the open (best), or chop the caps up & solder wick the leads out of the holes, then stick the new caps in. Replace these with 105C caps!
Helps, if you are doing this overnight, to fill the second coffee cup with caffeine based stimulant of choice to insure concentration.
Also, based on the 8100, this board has two little fuses that look like 1/4 watt resistors. They are mounted in little sockets. Best to have spares available before you begin if you and Mr. Murphy are not on the best of terms. In the 8100, these are 1 amp Pico fuses, don't know if the 9100 uses a similar scheme, but wouldn't be surprised.
The cards should go rather quickly. There appears to be a number of polarized caps shown on the schematics for the cards, which will mostly prove to be tantalums. On the 8100 and probably also the 9100 cards, usually there's just a pair of bypass caps on each card acrose the + and - 15 rails. Probably 100 uf at 25v--replace with 35v. I would also go with 105C caps here, since these things like to fail from heat in the 8100's.
Have fun and report back on your adventures!.
<P ID="signature">______________