I guess the bid Question is where did the OBE come from? If this is a new business, the balances are most likely equity from an investor of some sort. Most likely the owner. So a JE to equity to zero out the OBE would be the right thing. If it's a continuation of business and you're changing software then offsetting the OBE with the retained earnings of the date just before the start date of the new books is they way I would do it.
Let me know if you have any further questions.