Make sure you have CWM Installed
Make a full backup, as with every other ROM
Wipe cache/data
Wipe battery stats
Download ROM and install:
pa_tass-3.15-26ABR2013-020332.zip
Install this kernel:
http://d-h.st/obb
Reboot
Install GApps from KonstaT:
http://www.mediafire.com/?ss5khtjf9a5v4s9
Wipe Cache Partition
Reboot and enjoy