Right then, very simple. Remove the old amber indicator You will see that the wing has two rectangular holes in the end, what I did was to snip the end of the wing so the holes are now slots, and simply bend them round to the outside of the vehicle (dont forget to put some paint on or it will go rusty!!) 
Then you need to adjust the old bracket that holds the old lense in place, there is a 10mm bolt head behind the bracket and you can get at it easily with a flatish spanner, losen it slightly and rotate towards the wing, you only need to go about 45 degrees, this will now act as the stop/support for the new lense. 
Take the new lense and drill a hole in the bottom support, then I used a piece of aluminium plate about 30mmx50mm and drilled a hole just off centre, then simply rivett the aluminium to the lense, you should be able to rotate it to wherever the support is needed for your own vehicle (Isay this cos mine was slightly different each side). 
You can now fit the lense back in place, it doesnt need to click into anywhere as the spring on the new lense will hold it in place perfectly, it just wraps around the headlight support 
And this is what they look like from the front.... 
Dont forget you will need Mk5 indicator bulb holders! The Mk3 ones will not fit with any amount of modification.
Aritcle written by Rover.