http://golfgtiguides.co.uk/guides/remove-mk5-wing-mirror-and-change-indicator/ see the above site...
with your hand
Yes it does.
what are positioning lights on vw golf mk4
by putting a new one in
There is no light bulb in that can be changed, you have to change the entire panel. Only the agents carry the panel.
As you open the bonnet and look into the back of the light you will see a black tab like appendage there,quite low down (directly below the "flash", high beam side) but clearly visible, there will not be any wires connected to this and it wouldn't be obvious that the bulb is behind this! All you need do is twist and pull, viola there on the end of the appendage is the bulb and can be changed over quickly just as any normal indicator.
Yes the light bulb is replaceable.
Left or right hand side?
To change the brake light bulb on a VW Golf MK4, first, open the rear hatch and locate the tail light assembly. Remove the screws or clips holding the tail light in place, then gently pull the assembly out. Twist the bulb holder counterclockwise to release it, replace the old bulb with a new one, and reassemble the tail light by reversing the steps. Ensure the new bulb works before closing the hatch.
your bulb is faulty- replace it
You can find a nice D.I.Y. with pictures here: http://laudeman.com/volkswagen/golf_headlight.html