Pruning Lilac

My lilac bushes are 15 feet tall. Is there anyway to cut them down and still have them bloom? I want them about 5-8 feet tall.

Prune lilacs right after flowering next spring if you want to preserve the floral display. Cut back ¹/₃ of the larger stems to ground level. Next reduce the height of the remaining stems by ¹/₃. Repeat this for several years. By the end of the third year you will have a smaller shrub green with leaves from the ground up.