This doesn't seem like a straight 'plug in' job to me Saaz. I have had a head light go out, first one in the life of the bike. Does the H4 plug straight into the standard 1300 head light or are modifications required? How much 'tupperware' needs to be removed to replace a bulb?
H4 question already answered above
I just trim bottom 2 tags and don't use rings......if trimming use snips and don't be tempted to reach for your Dremel......will kill the globe
As far as plastic to remove NONE
Centre stand, reach in from underneath and twist bars to create the most room......plug off, rubber off, bulb holder clip released. Bulb out and new on in
Seriously a 5 minute exercise