Posted: 06/06/2016 at 13:45
Viburnum opulus is deciduous.
This will take any amount of hacking back, I usually do mine in winter.
Now, I'd remove anything that's dead or nearly dead, right to base. If it has lost roots it would help if you reduced some of the top growth as well. You could leave it with the OK bits on the lower right. Unless you've killed it by hacking its roots it will survive the prune