Or as an alternative title “Liberating your Galaxy S4 Hardware from Samsung Bloatware”.

Unfortunately there is lots of (ad-infested) blogs and forums with dodgy pieces of information on this topic and I found it pretty hard to get descent concise information. So hopefully this might help some poor Linux User liberate their phone. Whilst this has been tested on a Samsung GT-I9505 S4 International LTE device (JFLTEXX series) it should be applicable to other similar Samsung phones that are not fastboot capable (ie. all but the Galaxy Nexus range).