When amending a return, how to handle refund on 1040x

When amending a return with the on 1040x Form, how do I handle a refund I got? I put in all the numbers from my K1 and that was great. My problem is with filling out lines 18-23 - Refund or Amount You Owe. I received a refund but with the new information, I now owe more taxes, owe money to the IRS.  The instructions in i1040x_instructions.pdf from the IRS say "It is as if you were using the new information to complete your original return." OK. I can adjust all the values. That would mean that the taxes would be larger and the refund smaller, but I got the refund already. There is no provision for that. Should I just change the value of the taxes up and the refund down and send them a check for what I owe? How should I handle that? Thanks much, M