It largely depends on the student. Some have been able to do this, but not many. But the best chance you have of learning on your own is with this magerial and using Bill's free online class at teknia.com.
Teknia.com and the Basics of Biblical Greek (BBG) Workbook are indispensable. I would not try to learn BBG without the Workbook. The answers to the Workbook are available at Teknia. Be sure to check your work.
Any language is hard to learn
Any language is hard to learn on your own, but if you really commit yourself to it, it is possible.
It largely depends on the
It largely depends on the student. Some have been able to do this, but not many. But the best chance you have of learning on your own is with this magerial and using Bill's free online class at teknia.com.
Resources and Motivation
Teknia.com and the Basics of Biblical Greek (BBG) Workbook are indispensable. I would not try to learn BBG without the Workbook. The answers to the Workbook are available at Teknia. Be sure to check your work.
Also, take advantage of the flashcards for Anki and Mr. Peurifoy's class handouts, both of which which correspond to BBG.
http://www.teknia.com/news/02-05-2009/flashcards-anki
http://www.rpeurifoy.com/Greek.aspx
Pay special attention to the chapter summaries in BBG, review that material regularly and know it.
Lastly, before deciding whether or not to dive in, read what Dr. William D. Ramey's, "Why Study NTGreek?"
http://www.inthebeginning.org/ntgreek/introduction.htm