We have a rather old and tangled Lilac in our small city garden. It's about 20' tall with one fairly separate and upright trunk about 6" - 8" diameter one one side and multiple tangled trunks and stems on the other, all at an angle outwards. It's suckering everywhere as well. It still flowers well.
It's nice to have a tree and some shade, and it's lovely when it flowers, but this thing is probably long past its best and definitely needs taming. Some photos might help:
The options seem to be:
1. Prune heavily, but I don't think that's going to solve the basic problems.
2. Cut the bulk of the tangled stems away, leaving just the most upright old trunk. Trouble is, that'll leave the branches / foliage very one sided and I don't know if it'll come back.
3. Cut the whole thing down to about 6" - 8", remove all the tangled and worst trunks and hope it grows back as a bush.
4. Kill it completely and look for something to replace it with.
Any thoughts or suggestions?