I am going to be attempting an upgrade from 1.x to 2.x on a test site, but I find myself confused about how to handle add-ons. At what stage do I restore add-ons that are compatible with 2.x and how is this done?
Should I copy them into the 2.x folder before I start uploading it, or should I upload them after the upgrade is done?
Do I place all third-party add-ons—modules, plugins and extensions—in the third-party folder, and do I have to create separate folders for each of them?
Edited to add: Largely resolved, though I wish the upgrade instructions had warned me to uninstall any potentially incompatible add-ons as one of them ended up leaving a field-type behind that made the whole site unviewable.