There are a couple of ways on how to change the name of your assets. 

1. The first method is to change the asset title in Preview View. Click on the title and you will be able to change the title. When you are finished, simply click out and your new title will be saved.
2. The second method is to switch the view to List View in the Main Library, Workspace, or Upload Links (during the Review process) and just click on the name to quickly edit the filename. 

Note: Please note that a pure rename function for multiple files (batch edit) does not exist. However, you can use the Find and Replace function.