Firstly access your xoops database through phpadmin or whatever program you use.

Go to the xoops_users table and click "browse". Note your "uid" number which will probably be "1"

You will see the "group ids" listed by browsing the xoops_groups table

Then go to the xoops_groups_users table and click "browse". Then find the row with your users id = "1". Notice the "groupid" column you should be in group "1" which is webmasters. So you are in group 1, and have a user id of "1".

If for some reason this is not "1" click "Edit" for this row and make yourself a "1" again for the groupid column.

Then go to the xoops_groups_permissions table and look for the "gpermname" column. Then look for all the "system_admin" rows.

You might find them in later pages. Edit each system_admin row and change the gperm_groupid to "1" which is the webmasters group.