Yep, I'd remove now.

Here's what you're in for, if they're left . . .

Tree (36m tall):
{{gwi:239803}}

Trunk (over 1m diameter):
{{gwi:239804}}

Resin

Take it out now. If you want that general shape, in a smaller version, the 2 arborvitae cultivars 'Green Giant' (matures at around 50', 15-25' wide) or 'Emerald Green'/'Emerald Beauty'/'Smaragd'* (matures at around 20-25' x 8-12' wide) might do. If both of those are too big, T. 'De Groot's Spire' might work (12-15' x 3-4'). If none of those appeal, how about a holly? There are various cultivars, with various growth habits - some judicious pruning might help with height and width, although it's better, IMO, to start out with one that will grow as you want.

* I don't know if these are all the same cultivar, with different nurseries giving them different names or not, but they all grow about the same, and look about the same.

Boy I wish I new what cultivar it was.

"* I don't know if these are all the same cultivar, with different nurseries giving them different names or not"

Yep, same thing. 'Smaragd' is the cultivar name, while "emerald" is a translation of it.

"'Green Giant' (matures at around 50', 15-25' wide)"

'Green Giant' gets nearly as large as Leyland Cypress if not larger in the long term; mature height can be expected to be 30 metres or more. It hasn't been in cultivation long enough to know exactly how tall it will get, but its parent species both get over 30m (and one of them to 60m).

Resin

Ccacc, I may be wrong, but I think there are very few cultivars of Leyland cypress - maybe one other. And I think they get tall, and are, in this area, prone to disease/insect problems, as well as tending to fall over in strong winds with wet soil.

The alternatives I suggested are a different species, although with a similar look. So far, they seem to be staying healthy, with the exception of possible bag-worm infestations.

There's over 20 Leyland Cypress cultivars, though only 3 or 4 are widely sold.

Resin