Just done this on my 156, this thread was a great help
One thing I did notice though was when pulling the plastic tab to
actually get the old bulb out. Mindful of the numerous people who
have snapped this tab off I was loath to pull too hard, but the damm
thing didn't seem to want to shift. Wiggling it with a pair of pliers didn't
make any difference either, nor giving it a hard tug. Eventually I stuck
my fingers as far in as possible so I could grasp the base of the tag. To
my surprise the bulb and holder slid out with hardly any effort.
The difference was simply that I was pulling it in a slightly different direction.
So the moral is, if it doesn't come out easily you're not doing it quite right and
will eventually break the plastic tag off. Just keep trying in slightly different
directions until it slides out easily.
And thanks to all those who have donated skin in the cause