Newly bought quadplex

[Michael Burke]

Hello.. just bought a quadplex it was built n 1985 so some work is needed. I have tenanats already they pay 550 a month.. which is pretty cheap. It's a 2bed 2 bath. 2 units are 900 sqft and 2 are 1100 sqft. My question is what can I do to raise the rent value. All the appliances need to be modernized well basically the whole place. Any suggestions are well appreciated..