The pic was only to get the clocks out as I don't think you will find room to do anything from underneath
I've been doing some searching and I think you must have a SJ419, a diesel engined version that the Santana factory in Spain built in the late 90's.
Found a photo, lovely dash compared to mine.
This appears to have the same dash as the coil sprung samurai (not sure where that was built).
I have a workshop manual for the coil sprung version,so have put this together from what info I can find.
It says to remove meter cover (4 screws), but doesn't show where they are.
The parts diagram hopefully helps with that.
Please be aware the wiring diagram is from the coil sprung version workshop manual and may not be the same as the SJ419 (assuming I'm correct about you having that