You need to cut the part of the picture you want to use out of the original frame and paste it onto another background, or paste the picture onto another picture and then mask the parts you don't want to be seen.
There are several helpful tutorials available online, a quick search ought to bring them up.
try GIMP its free
If you are new to Photoshop you can try these tutorials for changing background http://www.photoshopsociety.org/basic_tutorial.php Hope you will find those useful
Adobe Photoshop, Adobe Photoshop Elements, GIMP,
Image > Image Size
Adobe Photoshop CS5
Adobe PhotoShop is Avery competent image processing tool with advanced features.
Adobe Photoshop CS5
Adobe* made Adobe Photoshop.
Adobe Photoshop is not multilingual. You must buy or contact support for localized version.
All of them, the Macintosh computer was made for graphics and picture editing programs such as Adobe Photoshop.
Press all modifiers (Alt + Ctrl + Shift) while starting Photoshop CS4 and later or delete preferences file:Vista & Windows 7 or 8Users/[Username]/AppData/Roaming/Adobe/Adobe Photoshop [verzija]/Adobe Photoshop [verzija] Settings\Adobe Photoshop [verzija] Prefs.pspWindows 2k/XPDocuments and Settings\[username]\Application Data\Adobe\Adobe Photoshop [version] \Adobe Photoshop [version] Settings\Adobe Photoshop [version] Prefs.pspFor example:C:\Documents and Settings\Bojan\Application Data\Adobe\Adobe Photoshop CS6\Adobe Photoshop CS6 Settings\Adobe Photoshop CS6 Prefs.pspMac/Users/[Username]/Library/Preferences/Adobe Photoshop CS6 Settings/Adobe Photoshop CS6 Prefs.psp
You must buy localized version of Photoshop. Adobe Photoshop officially does not ships as multilingual.