First, you will need to go to your home page. To do so, click on your profile picture in the top right corner. Click on your picture and then on 'my profile.'

Underneath the purple box, you will see your 'custom URL link. Click on the pencil icon and change it to what you'd like.

Please be sure to hit confirm when you're done. You can change the name of your URL link at any time using the steps mentioned.