How To Reset Your Sony Xperia L:
On your Home screen, tap Apps.
Go to Settings, and select Backup & reset.
Tap on Factory data reset. (If you want to delete all your files which is saved on your internal storage, then mark the Erase Internal Storage checkbox.)
Then Reset phone.
Confirm by tapping Erase everything.
You just need to wait while your phone deleting your files and restoring your settings to default.
Hard Reset:
1. If your phone is turned off, just press and hold the Volume Up and Volume Down buttons.
2. Then press and release the Power button (just keep on holding the volume buttons). There should a menu will appear on your phone.
3. Press the Volume down button to navigate to the Recovery option. Press the Volume Up to select (if that doesn't work, use the Power button to select).
4. An Android logo will appear. Press the Volume Down and Volume Up button together and a recovery menu should appear. Use the Volume buttons to move to the Wipe data/Factory reset option and then press Power to select.
5. Use the Volume Down key to choose Yes and press the Power button again to select.
