how to prune a lace lady tree

Assuming this is the False Acacia - you don't say what extent the damage needs pruning, or how much of the tree is affected by possible frost. all the advice i've seen says avoid pruning robinia as they really don't like it. However... I've pruned by a third to two thirds new thin growth at the bottom of a 10-15 yr old tree, to leave more space for the shrubs under it. the tree didn't seem to notice. Same tree had some die back on one of its top branches a couple of years ago. We cut out the offending branch. One very dry summer all the leaves drooped and fell early. I think that is common when it feels stressed. We left it, and it came back all right the following spring. hope this helps. Have only ever pruned late summer/early autumn. So far tree has recovered from everything!