There is currently no way from the GUI to update the license from the GUI
The only way I know of to do it is to reset the configuration in the database (which also means losing your configuraton)
If you are still in early stages and this can be done then the procedure would be as follows
reset configuration can be done using the following command at the CLI:
application reset-config acs
Note that after you reset the configuration when you login to the GUI will act the same as after a new installation. It will prompt for new admin password and then license (you can now use your new license)