Pruning trees back for more light

Depends on what kind of treees they are really, some trees respond well to pruning & others don't.  It might be a good idea to find out exactly what they are before you start on them then you can find out what kind of treatment they will respond best to.

Thanks, sounds like a good idea to me.  I might find it best to prune em down further, for example.

................ Or even kill them completely.........?
You might even consider offering your neighbour something in return for losing his trees altogether......? Maybe a few fence panels and the promise of a few veg from the increase your garden will see in productivity?
Or some rooted hedge cuttings ........... He/She/They can tell you what type..... And you take a few cuttings from an overgrown example you've seen somewhere walking the dog or taking the kids to school, for example....... Worked for me once!
You're lucky to have friendly neighbours, one of pair I have now is not so keen to help anyone or anything, and my patch is getting more and more shaded as time goes by.....

Anyways, I hope I've given you a couple of ideas... Good luck.

Nigel.

Ash trees rarely die from being pruned, and have an amazing ability to recover really rapidly as well, with a mass of whippy shoots.

At two foot in diameter though they sound pretty massive trees to cut down ... 

Imo, it's probably a self-seeded ash, in which case, if neighbours willing, I'd cut it right down. Ashes make enormous, fast-growing trees. You'll either end up with a monster, or you'll be fighting it all the time.

They sure do spring up quickly all around our school site and woe betide us if any get missed as they quickly turn into substantial trees --- maybe I should offer a bounty next spring 

If you want to help make a start killing the tree dont wait until the leaves fall as it means the sap would have gone back in to the root system.  We start coppicing mid to end of november and this is what you will be doing if yo leave it much longer.

Go for it they are a hardy tree and will need quite a bit of help to kill it off.