I agree with scootermm that leaving the print in the developer longer than the usually specified 2 minutes is beneficial. I find 3 minutes to be about right (but longer shouldn't hurt) and that most of the yellow is removed by this point, at least with K Ox developer.

Since you have Kodak HCA and citric acid on hand, first try clearing in 3 successive baths of HCA diluted 1:4 from stock. If that doesn't do the job, add some citric acid to it - maybe 1 tbsp per 2 liters.

Please let us know what ends up working for you.

- Keith