this is how I learned Hotel California;
B- F#7 A E G D E- F#7
what we have here is a modulation from the key of B minor to the key of E maj(or A maj depending on how you hear it) then to the key of Gmaj then back to the 5 chord of B-
what you described is known as a Picardy 3rd, where you take the 4 chord of a major 1 4 5 progression and turn it from major into minor, a technique often used by the Beatles and found in many Gospel changes.