Thid ROM is taken from Russian site mai.ru, but is no more (404). To install, you need to uses CUASAR Lollipop ROM, find elsewhere on this ROM Category, use SPF Tool to flash the ROM on your phone. that will give you TWRP Recovery.
Using TWRP Recoverey, then install thisd ROM, that you have downloaded and put on the external SD Card.
Credit is due to trhose in russian site and Cuasar for opening trh eman to install lollipo on S660
Disclaimer: I will nort be responsible for any bad result tp you who try to flash this ROM, your phone briicks, explode or divrocing from your wife/husband.