Here's a write up from another ST1100 owner:
Here's what I did: (Now, mind you, you do have to have a certain degree of
dexterity with each hand. Mine aren't so small, so size has little to do
with it).
OK. With the bike on the center stand, I turned the handlebars
to full lock RIGHT.
1) I used my LEFT hand, reached in, past the vanity cover and fork tubes and
accessed the boot that seals the bulb (it's a straight shot!). This is the
second hardest part about doing this - with the forefinger and middle
finger, pull the tab on the bottom of the boot firmly until it releases.
2) Then just push the retainer wire IN and UP (counter clock-wise). From
this angle, it's easy.
3) Remove old bulb.
4) Now (this can be the HARDEST part of this operation) push the retainer
wire out of the way and hope it STAYS there. Insert new bulb. This is
fairly easy (unless you're wrestling with the retainer wire too
. To
align properly to 'seat' the bulb, simply look into the front of the
headlight, and you clearly see where the 'dark' is, and move the bulb in the
direction of the 'dark' area in the center of the reflector. You will feel
it when it's right.
5) Swing retainer wire back to position, push IN and DOWN (clock-wise).
6) Replace boot. Plug it in. YOU'RE DONE. With one, that is.
Repeat the steps for the left bulb, using your RIGHT hand for that side, and
turning the handlebars full lock LEFT.
