Login into your IMDbPro account and access the Resume feature. Click on the edit button to edit your resume. Look on the left hand side of the page and you will see a list of links under "Resume Sections." Vanity URLs is the second link from the top. Click on the "Vanity URL" link and you will see the page appear. Enter your desired vanity URL in the open text field. Click save when you're done. Make sure you see a message saying your Vanity URL was successfully saved.