Upgrading from GreenHopper 5.1 to 5.2
Please follow the upgrade instructions in the GreenHopper Installation and Upgrade Guide, plus note the following:
Upgrading from GreenHopper 5.0 or earlier
In addition to the above, please read the GreenHopper 5.1 Upgrade Guide and the Upgrade Guide for every version you are skipping during the upgrade. The complete list of Upgrade Guides is available here.