As for 976, as a pump replacement,
We tried... Diode change was easy if you have worked on fine mechanics before. , #2 JIS screw driver, soldering iron , anti stat strap, a pair of decent flat jawed 4" needle nosed pliers, and a soldering iron. You need quick drying epoxy to properly insulate the flying lead. On Kecked's new modules the case is electrically hot, so mind your insulating technique when wiring drivers and heat sinking. Keck's new laser pulsed and flickered until we had the drive current well above threshold.
The factory girl did not tighten the backplate down, so I did not need to dig out the adjustable dual point optical wrench to unscrew the back plate, which holds the diode assembly. I got away with using the Pilar tips in the drive holes. I would not remove it if you do not need to do so, the crystal is very tiny and they went out of their way to glue it down with respect to any aberrations in the location of the focal spot. So the diode goes in first and then they aligned the crystal to its beam after it goes through a very tiny focusing lens.
Don't tear these down if you do not need to. There is a high grade molded plastic pre-collimation lens over the output face of the crystal. it would be very easy to knock it off. The diode holder "could" come out, but tearing down the rest of the laser, which is designed to be well sealed, is a no=no for a beginner to DPSS techniques.
Steve