1.Copy the rom (zip file) to the root of your sdcard
2.Backup your old ROM, so if anything is broken you can just rollback!!!
How to backup:
Press powerbutton and VolumeDown (leave volume down pressed). After afew seconds, recovery will open
With volume keys, go to "backup and restore". Select that option
Now select "Backup" and wait
3.Once backup complete press back button to go back to main menu
4.Select "wipe data/factory reset"
5.Go to submenu "mounts and storage"
6.Choose "format /boot" "format /data" "format /cache" "format /system" "format /sd-ext" - confirm every action
7.Return to 1st menu and goto Advanced and Wipe Dalvik cache
8.Return to 1st menu and choose "install zip from sdcard" - "choose zip" and chose RacerMod 1.5 alpha 1 zip
9.After installing, do "reboot system now"