Pruning rambler rose

My rambler hasn't been pruned for a couple of years


Is it OK to prune it now? in December

If not, when should it be done?


How best to prune it?

 

Yes, now is the perfect time. Any time up til March will suit it just fine. Cut out all the dead or old branches. Others can be cut back as you choose. You will probably want to keep a few long ones so just trim these.