The OFHG is pretty easy guys, most important thing to remember is to REMOVE THE NEGATIVE terminal from the battery, and isolate it.
Just a heads too, if was to do this, I'd be doing oil separator and all associated hoses at the same time. So much easier to do the oil separator etc with the alternator and OFH removed.
KPM_330 - if you need help dude, just shout, happy to help you or anyone else out.