You can use the Register dialog to field-upgrade a dongle.
If you have previously been issued a FlexPDE version 4 or 5 dongle, and subsequently purchase an upgrade, you will be sent a software key which encodes the upgrade.
Note: Dongles issued with FlexPDE version 2 or version 3 cannot be upgraded to version 5. You will be sent a new version 5 dongle when upgrading from previous versions.
Click "Help | Register" in the main menu. The registration dialog will show you the current state of your license.
Now check the "Upgrade" box. Your Register dialog will look like this:
Type or paste your upgrade key in the field provided, and click "Register". Your dongle will be updated with the information encoded in the key.
Note that the dongle upgrade facility will rewrite the dongle only if the serial number of the dongle matches the serial number encoded in the upgrade key. (This is not the "Computer ID" listed at the top of the dialog, but the serial number reported after the "Dongle" radio button.)