How to fit an M1.6 x 4mm screw into it's location?

[Aerodyne]

I'd suggest for any future similar tasks that you obtain a low cost set of headband magnifying glasses. I bought mine from Ebay and used them today when replacing a screw in the frame of my wife's glasses. At 76 and suffering various age-related eye problems, I could not have coped without the magnifiers. Well worth having on hand. There are many types available, most of which fit like a pair of glasses but like me if you already wear glasses, the headband style ones will fit over them.

Tony