1)  Find your "servername_charactername_uisettings.ini" file in the EQ2 folder. Rename it to "servername_charactername_backupsettings.ini". This way, you have a backup, if something should go wrong.

2)  Rename the appropriate "permafrost_windowsize_uisettings.ini" file to "yourservername_charactername_uisettings.ini", and copy it into your EQ2 folder.