creases

Your photo has more than crease damage, but here is an idea of what can be done with it in the Guided Edit.  And, if  you have some patience, you can get a better result than my 5 minute edit.

There's the Restore Old Photo guided edit which walks you through the steps involved in repairing old scanned photos. You can access it in the Photoshop Elements Editor by going into the Guided Edit mode, and then the Special Edits section.

Some sections from the Photoshop Elements User Guide that will be helpful:

Restore Old Photo guided edit

Remove spots and unwanted objects

Fix large imperfections

This article, taken from Photoshop Elements 7 Classroom in a Book, might be helpful too (especially if you are working with an older version of Photoshop Elements):

Restoring a damaged photograph

If you are a novice, it would be a good idea to use the Guided Edit>Special Edits>Restore Old Photo guided edit.  It provides you with the necessary tools with some instruction how to use them.