Extending Visa

Hello I am looking for advice on extending my stay in Belgium. I am a Canadian legally living with my Belgian partner under a 1 year working holiday visa and looking to have it extended from either 6 months to 1 year. Our plan is to have my partner then apply for Canadian PR and we would like to still be able to live together during that process. If I were to marry my partner would that be a way of extending my visa and if so, what is the applicaton like? Thanks