You should be able to trim back almost to the ground and it should send new shoots out. I doubt it would bloom again this year but you never know. The safe thing to do is cut it back hard and propagate the tops either in water or some fresh potting soil. Water rooting is very easy - I stick some cuttings in a bud vase and place it on the kitchen windowsill for example.

Here is a good site for questions:

Brad's tips

hcmcdole,,

thanks so much, i'll take a look see and write some things down.

miss daisy