how to apply pardon for conviction

Hello,

Everyone!

I have a question about pardon for conviction. I am a Chinese boy and once got the Canadian Visa in August 2004 and had studied in Canada for over three years. But for my passport was expired, I came back China for re-apply my Canada Visa. I was refused to enter Canada again for a light traffic accident of running a red light in Canada. The reason for refusion is that I violated the A36(2)(a) of IRPA. The visa officer told me that I must apply for and receive a pardon for conviction. So hereby I want to know how to and where to apply for pardon for conviction. Anyone who knows please help me. Thanks a lot.
There is only one-year to get my bachelor's degree in Canada, I hope to complete my last courses.