ninni - I tried this myself, without much success. I took off all but a few top leaves, but those dried up and fell off, so I've got a stick in the dirt now

I pulled it out, thinking it was dead, but saw some roots! I put it back in the pot, and will just let it sit and see what happens. Is the mamma
plant on your property? I think what I'm going to try next is 'wounding' a sucker and burying the wound in the soil, letting the mamma help it along and it will establish it's own root system. At that point I'll cut it completely away from the mamma and replant. Keep us posted on your progress - I will too...I LOVE
lilacs, and just have to have them all over the place now that I've had one for a
spring of awesome fragrance throughout the yard and even in the house!