Remove or move things you no longer need on your Lumia Windows Phone 8, use the Storage Check application. Go to Settings > Storage check, swipe over to the Details view:
Delete browsing history, temporary files, cookies and saved passwords in Internet Explorer (Settings > applications > Internet Explorer > delete history).
Delete previous map searches and temporary files from your phone (Settings > applications > maps > delete history).
Delete Bing search history, including Bing Vision and Bing Music searches (Settings > applications > search > delete history).
- Remove offline mixes from MixRadio: Select MixRadio > offline mixes, long tap any mix and select Delete.
- Remove downloaded maps from your phone and clear temporary files.
- Tap on apps details to find out what apps you have on your phone, consider uninstalling some of them to increase the space in your phone memory.
- If you have a PC, connect your phone to a computer with a compatible USB cable. On your computer, use the Windows Explorer and browse to your phone to see a list of the folders: Documents, Music, Pictures, Ringtones, and Videos. Right-click the file you want to move, click Cut, right-click a location on your PC, and then click Paste.
Delete browsing history, temporary files, cookies and saved passwords in Internet Explorer (Settings > applications > Internet Explorer > delete history).
Delete previous map searches and temporary files from your phone (Settings > applications > maps > delete history).
Delete Bing search history, including Bing Vision and Bing Music searches (Settings > applications > search > delete history).