If all you want is to update the recent changes, then you could just download one of the updates on this forum. This should save you a lot of time (& you won't be temped to make changes to "help you along".
If you do want to make changes, then load the database using the editor (back up first) & you can search & change attribues & CA/PA where needed.
As for swapping teams to account for relegations/promotions - there is a long informatuve post on this forum that will explain almost everything better (& indepth).