credits to mikegapinski, mikeioannina, Mardon, Blefish, nobodyAtall, pcfighter
* Have the stock ICS 4.1.B.0.587 full ftf flashed (doesn't matter if you have flashed it in the past or if you flash it before installing cm11.0, it will work both ways)
* LT15i (Arc) users need to flash LT18i (Arc S) ftf
* MT15i (Neo) users need to flash MT11i (Neo V) ftf
* minimum 2GB secondary ext4 partition for /data on class 10 sdcard.
Steps required for correct installation (order is important):
1: Flash boot.img in fastboot & reboot into recovery
2 (optional): If the device is not booting, reboot to bootloader again and run:
fastboot erase system
3: Enter recovery
4: Format /system using System-Formating-Tool_signed.zip(can be found in downloads page) , then /data and then /cache (Important step!)
5: Flash update zip download from here:http://downloads.gapinski.eu/lxaosp/63gd7wgw/
6: Flash gapps-download from here:mdpi gapps:http://downloads.gapinski.eu/lxaosp/gapps/
Steps 2, 4, 6 are not needed when you install new LX build on top of an older one in the future.