Happy New Year Jasper,
To manually update go to top left of Airnav screen, click on file and on the drop down list click on Database explorer. When the box opens on the middle of the screen change Select Table to Aircraft. In the box yo the bottom Text to find, type in the registration of the aircraft concerned, Condition to By and Field to AR. Click Find and the details should come up on a line at the top of the main box.
Ckick on the cell you want to change AT, it will turn blue,click on edit cell that will allow you to make the change you want, make the required change then click anywhere in the main box to save the change. You can then move on to the next aircraft doing the same.
Alternitivley at step one you can put A380 in the Text to Find box, Condition By again and Field this time will be AT and any A380 will be found
Alan