FLASHTOOL
- Download and install the latest Flashtool version on your PC
 - Download the desired firmware (.ftf) and put it in the /flashtool/firmware folder
 - Open FlashTool and click Flash
 - Follow the on-screen instructions: turn off the phone, press and hold the BACK key and plug it on the PC
 - Wait and... done (usually takes no more than a minute)!
 
xRecovery
- Download Busybox from the Android Market, open it and click install
 - Download xRecovery, open it and click install (the three icons must become green)
 - Reboot your phone and repeatedly press the BACK key when the SE logo pops up
 - A blue screen will show up. Navigate through menus with the volume keys, the HOME key and the BACK key
 - To backup your current rom, go to Backup Restore and choose Backup
 - To install a custom rom, go to Install Custom Zip From SD Card and pick the rom's zip file
 - Reboot phone and... done!