Prerequiste :
1. Clockworkmod recovery (CWM recovery) or other custom recovery
2. CM 10.1 ROM archive (.zip file). Download here if you haven't it already
Step by step :
1. Place the custom ROM on sd card
2. Go to Recovery Mode by press+hold Home and Power button together
3. Wipe data
4. Wipe cache partition
5. Wipe dalvick cache in the advanced option
6. Choose install zip from sd card
7. Choose CM 10.1 RC5 S5570 tass.zip
8. Install it (Wait until the process finish)
9. Reboot phone
10. Enjoy
