I was given a set of steps by robert.angus -- here is what he told me:
To start, you would need to remove all payments from within the bulk check. Once all payments have been removed, close the check and click yes when prompted with the "bulk check not complete" prompt.
Then click yes to the "no entries on the bulk check" prompt.
At that point the check will be gone and you can begin to repost it.
If the check is older than 90 days, it may not allow you to remove it completely. You might be able to remove the payments from it, but it will not allow you to delete the check. What we generally suggest at that point is to make the check amount .01 and post a penny payment to the dr to close it and then use a collection adjustment to offset it on the Dr's ledger. That way the check is marked as completed and doesn't just sit in the working bulk check queue.