I'd say just trim it gently! Not into old wood, though. Do you know which species it is?

Many thanks for this helpful response. I believe that is a Fraser Fir. At the moment it is approx 8 feet high (not an issue), but 4 feet+ wide. This isn't a problem this year, and it is really beautiful right now, but can see that it will become an issue soon as it is starting to encroach on 2 superb slow growing rhododendrons on either side of it. Many thanks once again

I found this article which might help.

http://www.ehow.com/how_8455200_prune-fraser-fir-tree.html