One 6mm hex wrench and 8 M4x12mm screws later, the monitors were mounted on the stand and reconnected to power and the computer.
It’s a pretty sturdy stand and seems to be holding my 21″ monitors pretty easily. I added an additional piece of 1×4 to where the stand clamps to the table as an additional shim and to help spread the load on the table top a bit more.
The monitors are up about 5 cm higher than they were with the factory stands, and a lot of space underneath the monitors is freed up. Pretty pleased with this setup.