Zos ti'hiyeh tahras hametzorah byom taharaso... The parsha then continues that the metzora comes to the kohen who must perform an exam and check if the tzaraas is cured. If it is, then the metzora may proceed to bring the required korbanos and undergo the process of becoming tahor. Shouldn't the pasuk of "zos ti'hiyeh taharas hametzorah" come after the kohen's exam, i.e. only once it is actually determined that the metzora is cured and can undergo the tahara process?
Aside from the physical blemish of tzaraas, the metzora needs to cure the bad midos that caused his punishment. Chazal tell us that no one can pasken on their own negaim. A person will always see themselves in the best light. Until a person is willing to listen to the advice and judgement of others, they are not ready to escape the pain of the tzaraas affliction.
Zos ti'hiyeh toras hametzorah... V'huva el hakohen. The very fact that the metzora is willing to got out -- to leave his comfort zone and preconceived notions -- and meet with the kohen to seek his help already proves that he is on the road to recovery. The cure of the physical nega is sure to follow.