Have 3 properties, how should I refinance this for maximum cash flow

[THANG BUI]

Hey everyone. My mother owns a home and two 4-unit townhomes. 

Current situation

4-unit townhome 1: principal remaining $523K @ 6.625%. Maturation date 12/36. Rent collected ~6500/month

4-unit townhome 2: principal remaining $163K @ 6.25%. Maturation date 1/18. 

Rent collected ~6500/month

Home residence: Priincipal remanining $91K @ 5.375%. Maturation date 12/17

I was thinking of refinancing the 4-unit townhome 2 and lower the interest rate and use that cash to pay down the 4-unit townhome 1. Perhaps also keep some cash to put down for another property. What would be the best way to go about this?

Thanks! I love BP