Headlamp removal

My Fiancée has a Nissan Micra K12 and the n/s headlamp has the common problem of a misty look inside the lens. We have bought a new headlamp and I was going to fit this myself but I just want to find out the right way of doing this before I dive into it. I am unsure of how to get to the clip/bolt that attaches the headlamp to the inner wing??

Any help would be gratefully appreciated.