Oops. Sorry, this is an st1300 reply to an st1100 question. Thanks Uncle Phil for subtly pointing that out in post #4. Think i'll go and lie down now!
It depends on the size of your hands, I think. I say that only because I have big hands, and I cannot get to the bulb holder from above. I can get my hand down, but there is not enough room to get my fingers onto the part of the connector that needs to be pressed on either side to release it.
So I try to get it from below. Sometimes I can do it, sometimes I can't. It made it much easier once I had practiced a few times when I had the fairing off, and had put dilectric grease on the connector to ease things.
I don't know about MOT failure. Some bikes always run with one beam turned off. But Uk has an 'if its fitted, it must work' rule. Ask them before you go.
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I thought I had posted this article on here years back, but can't find it. I'll add it to this post when I get a chance. In the meantime, this may be of some help:
http://www.jfheath.co.uk/st1300/st1300-serv-headlight.shtml
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