can i add Developer License after purchase?

If i buy without Developer License can i remove the designed by footer when i decide i want to buy the Developer License later on down the line?

To upgrade your template order to developer license, please do the following:

1. Log in to www.hotwebdesigntemplates.com and select "Downloads", then click "Available Downloads".
2. Scroll down to see the "Account Addons" section and the link "Click to view available addons".
3. Click "Order Now" in "Developer License" field.
4. Make payment as usual.