Fillow the link in the dialog that is displayed when you run the software.
Or simply go to the following link.
http://www.plm.automation.siemens.com/en_us/products/velocity/solidedge/free2d/index.shtml To the right of this web page Click on the link 'I already have Solid Edge 2D Drafting and want to upgrade to the newest for FREE'.
Fill in the form on this web page and click on Submit at the bottom.
You will be taken to the download page.
Scroll down and click on the link to download the license.
This will be a ZIP file. The zip file contains a (.dat) license and a text file. The text file has directions for applying the new license.