Definitely best to upgrade one subsystem at a time, so as to limit the problem scope that you need to work through.
I followed the upgrade instructions[1] in the docs after upgrading to aolserver4.0.10 first.
1. https://openacs.org/doc/openacs-5-2/upgrade-4.6.3-to-5.html
best wishes to an uneventful upgrade! =)
