Need to post a cash transaction in a closed year.

I need to post a decrease adjustment in Bank Transactions and then post the equivalent in Cash Receipts in sales into Dec 2015, which is closed.   I have made journal entries before into a closed year and it worked fine.  But never cash.  I use bank rec too so I would have to reconcile those transactions in bank rec.   Anyone have any advice, comments? Can this be done?  Thanks.

Shelagh