[xwiki-users] Upgrade strategy

Hi, What is the best strategy for upgrading (2.7 -> 3.5.1) and making sure everything is based on the latest? I was thinking the following; Export the old Wiki (full Export) Delete the Wiki Clean installed Wiki Import the Export Import the XAR of a fresh Wiki Problem with above; With last step I overwrite and lose all modified pages (especially XWikiusers group) All imported pages are not modified to latest XWiki syntax profiles of XWikiUsers are based on OLD object definition Object def changes in BLOG (if any?) Script changes in Register procedure any other? Gerritjan