Should I say 'how' or 'ways' in the sentence. Have I correctly used the two 'on' in the sentence?

Should I say 'how' or 'ways' in the sentence. Have I correctly used the two 'on' in the sentence?

A year ago, Dr. Ford conducted a seminar that aimed/intended to provide his students some background information on tuberculosis and HIV/AIDS and on (how, ways) to prevent the spread/transmission of these diseases.