Hi, you can't really cut these, because they don't regrow from old wood, and the size of those, you would probably need to cut them in half to notice a lot of difference, I can only imagine what it costs to pay for them to be trimmed, would it be cheaper to buy a petrol hedge trimmer, that fits oto an extension pole, and a set of sturdy step ladders, and do it yourself, Derek.

For some reason I can't see your photo but several years ago I had a similar situation to yours.
My next door neighbour had a row of leylandii which had grown to about 14ft high, stopping the sun from reaching my patio behind it.
I asked him if I could cut it down 6ft and he said yes as long as I got rid of all the offcuts etc.
I did this, cutting them all to 7ft high ( an extra foot ! To match the back of my garage), and have been trimming it ever since, arriving at a very satisfactory hedge. The other side is a mess as they haven't looked after it at all but my side is fine.
I'd like to add a photo here but can't seem to do it so will try to send it to you personally.

Please ignore my reply ( above), I've just seen the sizes of you conifers and my suggestions are no use to you. I guess I got carried away.

Sorry you were carried away Hank, please come back!