Thank you for your question regarding pruning your lilac. Miss Kim lilac variety is best pruned following the decline of its blooms. You can remove all blooms down to the node they start at. Any branches that appear to be declining should be removed, with a sharp pruner or lopper down to the base of the tree. Miss Kim lilacs typically do not like drastic pruning. If you are looking to reduce your shrub's size prune gradually each year by removing larger branches down to base. Do not remove more than 1/4 of the shrub at a time.