There are two recordkeeping programs in the Aviation Hub; Profile & Compliance for just recordkeeping and ATP Maintenance for maintenance forecasting. I am going to assume the question deals with the Profile and Compliance program.
Because your question is about updating I assume the AD is already on the compliance report with the prior compliance information. There are two popular methods of updating compliance depending on the desired outcome.
1) Update the current record to show the latest Last Complied With information. Click the Edit button on the current record and update the complied with information. With this method there is just one record per AD with the latest compliance information, i.e. current status of the AD
2) Duplicate the AD to make a record of every compliance. In the right side Actions dropdown select Duplicate. The system will add a new record just below the one you duplicated. Enter the new compliance information. With this method you will have a history of all compliances for this AD.
I hope I answered your question and feel free to contact our support team at firstname.lastname@example.org