Step 1 - To assume the identity of someone who has granted you access, click on your name in the top left corner of Paragon
and then click Assume Identity.
NOTE: Assume Identity will not appear until you have been granted access to assume someone else's identity. If it is not showing, please have the other person grant you permission.
Step 2 - A list of who has granted you access will appear. Select the name you want to assume. 
Step 3 - Click Assume.
Step 4 - A warning pop-up window will open. Click OK if you do not have any unsaved information.
If you do, click Cancel. Save your work and return to Step 1.
Step 5 - You are now working under the user you have assumed the identity of. You can now add or modify listings data on their behalf or any work on any other functions that the user has access to.
You will see the name of the person you are working as in the top left corner and on the Home Page Message widget. 
Read this article to assume another identity or return to your own identity.