first make a backup of your old XF forums & database incase anything goes wrong. Then you simply copy all files from new xf 2.2.14 (or xf 2.2.15) over writting old files, then you run the url h t t p : //domainNAME.com/folderNAME/install - XF should detect it's an upgrade and not a clean install, then follow on-screen to finish the upgrade.