When you have a big option gain from an after hours EA, you have two issues to deal with.
The first is a reverse in the underlying prior to the opening of option trading the next morning. If your concern is locking in some of that gain, you hedge the position with stock. To do this in less than a haphazard way, you need to estimate the delta of your position and short shares for whatever portion you wish to lock in.
Yes, this makes the position more complex. Yes, It may cost you some money if RIMM moves up more (opportunity loss). But AFAIK, the last thing I'd want to do is see a large gain turn into a small gain before you even have a chance to close the options (RIMM drops big time before 9:30 AM).
The second issue is the obvious one that many have mentioned. IV is going to collapse in the AM. If it's big time right at the open and gets back to normal levels, you might hang in there if you're still bullish. If it drops but not down to normal levels, your best exit is ASAP since throughout the AM, IV is likely to drop more. Doing nothing is going to cost you money. The only reason to absorb that loss is if RIMM is moving up and your position is gaining in value.
If your bet is that RIMM goes higher, none of this matters. If you want to lock in and maximize the current gain, it does.