Completely lost about rooting/installing ROM on my S2!

Ok so I've just rooted my Samsung GT-I9100 with Odin and everything seems to be fine.

Now I want to install - SensatioN ROM 4.1 - http://forum.xda-developers.com/showthread.php?t=1194765.

How can I do this safely?

Model Number - Samsung GT-I9100
Android Version - 4.0.3
Kernel Version - 3.0.15-I9100XXLPQ-CL223505 se.infra@SEP-94 #3

I've backed everything up with Kies but I just want to load this ROM properly.

Thanks guys

You need to install it via CWM.

Before this though you'll also need to make a backup of your current ROM once you've booted into CWM, this is very important, in case something goes wrong with the flash or you just wish to flash back to standard.

Also do a backup of your efs folder.

Back up all the apps and app data using Titanium backup before as you'll also need to do a full factory reset/wipe, and wipe cache etc.

There are videos of how to do all this on youtube and loads of threads on XDA.

I'm about to leave work so can only point you in the right direction for now. But i'm sure someone will post links shortly.