Do you have the owners manual? There are clear-ish instructions in that for positioning.
When you go shopping for the
stickers, don't be tempted to buy the cheapest...
We drive down to Spain a couple of times a year and
always use these . Others we have used have dropped off.
Oh yeah - always ensure whichever ones you get are translucent and not opaque as this will fooook up the polycarbonate plastic of the headlights.
You will only need the circular bit and there is a sheet inside the pack showing
how to position them - but as the headlights are clear, it is not an exact science...