[Q] What tutorial should I follow in order to unlock this device running GB? topic

I feel a bit overwhelmed with all the tutorials that there are and I am not sure which one I should follow.

A friend of mine gave me his Galaxy Note N7000 because it was painfully slow. I have unlocked/rooted/flashed etc. several times other devices, but not with one as old as this one. It runs Android 2.3.6 and it is not OTA upgradeable for some reason. I Just want to flash a stable CM 10 ROM and leave it like that for the rest of its days.

Thank you for your time.