Just to put a different perspective on things, I've just spent several hours this morning trying to replace an old outside light with a new one, that my wife got for free, but "It's still in its box, so it must be OK". Take bits out of the box, but no instructions, several bolts missing. Still, nothing ventured, nothing gained, so I screwed the back plate to the wall, then realised that the bolts which hold the cover on need to be put into place in the back plate, so I removed the back plate. Then the bolts didn't protrude enough to attach to the covering nuts, which meant removing the back plate again, putting blue tack behind the nuts, so that they stay still/don't drop backwards. Finally got the light on the wall, but no bolts in the box for the cover/lid. I spent 20 minutes trying to find bolts of the right length and width, found two that fit, but look rather rough, and eventually we've now got a working outside light, which we had yesterday, but the 'old one looked tired'. So do I, so do I !!
So if anyone wants to try again with my outside light, I'll willingly take their place in the ticket queue, and get them their tickets (as long as they're paying)