Need help on increasing rents. New to landlording

[Nicholas M.]

Hi, I just acquired a duplex. I live in one unit and rent out the other. The other unit was acquired with a rent $400 below market rentals in the area. Im brand new to the game and I dont know whether i should just tell them im going straight up to the market price or slowly increase rent to the market price. They are prob gonna move if i go full market price. Should I slowly go up every month $50 or every 2 months or 3 months? or should i go full market price, have them leave, then try and acquire new tenants for the full market price? The tenants have been there for almost a decade. Anybody have any experience with this type of thing? im in a hot location that is pretty much zero vacancy. 

Thanks-

Nick