RpR said:What do you mean by buckets?
robynanne said:I bet you could cut the bucket free and just plant the tree where you want. Water it really really well for 24 hours first, cut, replant right away, keep watered and give it root grow fertilizer for a few weeks, then watch really close to make sure it is watered well the rest of the summer. The alternative would be to cut the pot off around it and dig out the roots.
When I moved a tree, I was told to trim the branches because the roots would be getting severely cut down and it wouldn't be able to support all the branches, so I needed to balance it out by pruning the branches down too. I'm not sure if lilacs are the same way. They're pretty hard to kill though.