[i9100] - How is the best way to get to CM12.1 for my device?

Hi Guys,

I've just put in a new motherboard as my old one eventually died and it's current details are:

Model: GT-i9100
Android Version: 4.0.3
Baseband: I9100XXLPH
Build Number: IML74K.XXLPH

There is an update available which I assume is an update for JellyBean 4.1.

How/What is the best route to get this phone from it's current ROM to CM12.1?
Am I correct in thinking I should update it to Jellybean 4.1 then flash a pit file (I91001GB_6GB.pit) with CWM (CWM-KitKatCompatible-i9100.zip) and then just wipe the storage & install CM12.1 via CWM?