Duplex: refi or sell?

[Erin Schreiber]

I have to either refinance or sell a duplex in the next 6 months as part of divorce proceedings. Currently, it is rented under market value, grossing $2700/mo total , with a monthly mortgage payment of $1561, and me paying utilities around $500. I could raise the rent to probably $3100/mo total. I could pay about $6000 to have a second electric meter installed, so the tenants would be responsible for utilities. 

I’d guess the property value right now is above $450,000, and I currently owe $150,000.
I’d hate having to pay capital gains on a sale, so I’m leaning toward just refinancing. Is there a specific tool I should use to make this analysis? Or a rule of thumb I should lean on? Or additional info I could provide here to get recommendations?