From what I can tell, the assembly is the reverse order of disassembly;
"6.10.3 Anti friction bearings
Antifriction bearings should be preassembled so that
the complete bearing set can be mounted on the
pump casing. To do this, reverse the dismantling in
sections 6.8.2 and 6.8.3."
In 6.8.2, the Thrust bearing is the first to be removed, so it should be the last to be installed.
I'm not sure if this helps, but I would say that the radial bearing should be locked first.