Are you trying to get the program out of an existing Series Three so you can translate it? If so, every Series Three has a programmer attached. You can step through the program and transcribe by hand.
Beyond that, there were two other vehicles for programming the Series Three. One was the Portable programmer IC610PRG110. You would also need the Series Three program Pack IC610PRG117 and appropriate cables.
The other was Logicmaster Three software which was so buggy that GE Fanuc withdrew it from the market rather than commit any resources to fixing it. The Series Three never developed much of a following.
Try calling around to GE Fanuc distributors who have carried the product line for a long time. You might find someone who still has a portable programmer hiding in a dark corner. You might also check at PLCCenter.com, Qualitrol.com, or on eBay.