sorry M2.5 nuts, not M3 been trying for some time - tweezers, tape, gravity... no chance of getting a finger in there
If I recall I used a tiny jeweler's screwdriver to hold it in place on one hole, then put the first screw into the second hole. Once you have one in, the other is easier.
aha - bad choice of nuts, my fault in Fixings Bag 4 there are M2.5 hex nuts (not square, as pointed out in manual) and then something even smaller, perhaps M2 or M1.5 (with which I've been trying with my father for half an hour!) should work now
And afterwards, I recommend a fine 18 year old Macallan... Those screws were barely visible for those of us approaching 50 (although the set screw on the hobgoblin is way worse...)
Haha... here the comedy continued. Now equipped with the right screws, son went underneath the offending part equipped with the allen key; father stood above peering over (or under) his half moon specs (his vision even worse than son's), looking through a hole in the top of the IR sensor through which he was simultaneously poking the jeweller's 'driver into the nut and the centre of the bolt-end which turned from below. Pretty much the sort of thing we'd been doing for some time, but this time - of course - it worked. Cigar!
Already got the Glen Morangie and Blue Sapphire in the toolkit, now all I need is the BigBox (backer 499). Got to order the tonic and lemon! Mike