I went and sorted some spots the other day, i found places with rich soil, in dense brush.. so it was safe, i dug a few holes, clipped out a few roots and thorns, added some chicken manure, turned the soil thoroughly and walked away..

use a big shovel, make holes big, and if the roots in the area are too aggressive, cut the bottom of a pot out, and slot that in the hole, try to make sure the bottom of the pot is below most horizontal roots, and you should be ok..

there are a few things to do in preperation, but the bigger jobs come when the plants do. - good luck..