if you filed, you start with the amended return option, delete the credit and related forms depending on where it was entered. do not file an amended return until the original is fully processed. filing an amended return too soon can delay a refund for 4 to 5 months.
if you haven't filled delete the entry that created the credit and the related worksheets and forms
Note certain but other steps may be needed to clear out the credit. This depends on what the credit was for/
