Go to the Media tab on the VSM menu.
Select the File Manager category listed underneath the tab.
On the left hand side of the page, select which folder your image is in.
Once you have selected the correct folder, a list of images in that folder will appear on the right hand side of the page.
Find the file you want to rename.
Once you have found the file, click the rename button corresponding with the correct image.
Under the New Name box, input the new title of your image.
Click the blue Save Changes button for your image to rename successfully. The new name will appear.
Since the images are listed alphabetically, your image may be in a different spot than it was with the previous title.