If you want to hard reset your Sony Xperia E5 then you can follow the instruction below to put it back to the factory settings. You will note the options below to reset the mobile phone. Also note that once you have done this you will not be able to recover the data or your phone settings again.
If you wish to backup your data then you will need to download the Xperia Companion to connect your phone to your computer in order to backup your settings and data. The software will also allow you do do a reset once the backup is complete. If you are not in need to the settings or data then you can use the easier methods to do the reset as listed below.
Hard Reset will erase all of your data
All described operations you are doing at your own risk.
Hard Reset Sony Xperia E5 with Menu
Hard Reset Sony Xperia E5 by Code