Originally Posted by cincinnana

Attempt to get as much soil with undisturbed roots attached to the plant.
I use a large knife to get precise cuts.

Just recenter the plant with the intact rootball in the new container using a good quality soilless mix and minimal fertilizer.
In a few months the roots will infiltrate the new mix and stabilize the plant.



Root ball
by
Hostafarian
,
on Flickr

. This plant was split in thirds with a sharp knife.
Each intact rootball was centered and planted in a new container to be grown out.
The rootball was minimally disturbed to preserve the hair roots.
.

Plants split with a knife
by
Hostafarian,
on Flickr