How big in diameter is the base of the plant? You don't need to dig the whole thing up, but I'm not going to give you any more advice until I have a better Idea of what you are wanting to divide. It would also help to know how long this has been in the ground, what fargesia species it is, and how tall the culms are.

It is a fargesia murielae that's been in the ground for 2 years. The base is about 1.5 feet in diameter and the bamboo is between 6 and 7 feet tall.

ikea-
That sounds good and do-able. Clumpers are sometimes harder to divide because the root system is dense and compact. If it were me, I'd try to take out two divisions, each about 1/4 of the base. You could take smaller divisions, but the smaller you go the more risk you have of the division failing.

You will need to have some kind of saw like a root pruning saw, or a Sawzall with a long (10"+) blade. Cut all the way around the division you are visualizing and then pry it out gently with a shovel or other prying device like a demo bar. If you take the whole plant out of the ground it would be a little easier to make divisions, but then you would setback the main plant by a year or two, so I don't advise this. Now is probably a good time to do this. Good luck.