http://free.grisoft.com/doc/24/lng/us/tpl/v5
Download the priority update(s), remember what folder it went to
Make sure your computer date and time are correct (AVG needs to know)
Launch the AVG Control Center, select the Update Manager button,
then press the "properties" button at the bottom of the window
UNcheck the option "do not ask for update source" and click "apply"
Click the Update button at the bottom of the window and find the folder
you put the download in
Click OK and AVG will update (unless it's already up to date)
Remember that you've set AVG for manual updates. You'll have to
undo that if you want to update via the Internet again.