There's quite a few clues in that thread. This, from Marty:
If any of those don't work as well, then it could be a problem at the splice for the power feed to the instrument cluster. The instrument cluster gets 2 power feeds from the same fuse - both purple wires, on pins 4 and 14 on the cluster connector. Have you verified there is voltage there between pins 4/14 and the instrument cluster ground pins (7 and 17)?
That purple wire contains several splices along its way from the BECM to the footwell lights. You might have to unwrap the black tape along the harness to find the break, measuring for 12V at various points, starting from where it exits the body module. When you find it, cut out that bit and solder and heat-shrink the join.
While you're in there, cut out and replace the multi plug behind the cover on the footwell with jumpers. (there's another on the other side that also corrodes). Have you pulled all the plugs from the back of the instrument cluster and hit them with contact cleaner? I seem to remember that one of those goes to the HEVAC unit from the cluster and that one gives trouble too.
The plug you linked to looks correct (or at least the picture looks correct showing a 10 way single row even though the description says it is 18 way 2 row) but you don't need the whole plug, just a replacement socket to slot into the housing. You can push a small jewellers screwdriver into the housing to release the existing contact and slot a new one in.
You say you're not technical but you've got this far. You don't need an auto elec to complete this repair. You're smarter than that. Good offer from RG to send you those clips but you can clip out each one in turn and slip it into its slot to test the fit. They should be a nice tight fit; gently crimp any loose ones so they fit snug. They go loose over time. That should get you going. OR you might find it's the connection between the wires and the connector that's gone green and corroded in which case you'll have to solder them or replace the clips.