Before you change the theme make sure to backup your entire site. Just in case something goes wrong and you can’t figure it out, you can always go back to that last backup.
Here’s how to change the Maron theme over to the Playcast theme:
View demo of the Playcast Theme here.
Depending on the hosting you have, they do daily or weekly backups of your entire database. For example, my Bluehost account they do daily and weekly backups of everything.
When I need a back up I can go in there and download the latest one.
So I would suggest contacting your hosting provider and find out if they do backups and how often. If they do then ask for the latest copy.