Q.pruning boxwood hedge
I have a very old (30 years at least) boxwood hedge, which is spindly and unattractive. Can it be pruned and, if so, how or do I have to take it out?

I would recommend that your boxwood shrubs undergo what is called a "renewal pruning" which is a multi-year pruning process which involves pruning it back in stages. Renewal pruning is described in detail here: https://extension.psu.edu/plants/green-industry/news/2012/hacking-whacking-dealing-with-overgrown-shrubs
For more information on the care of boxwoods, please visit the following links:
https://www.gardeningknowhow.com/ornamental/shrubs/boxwood/boxwood-care.htm
https://www.gardeningknowhow.com/ornamental/shrubs/boxwood/trimming-boxwood-bushes.htm