Confused about what to do with the IRS withholding calculator results

Hello all,

I’ve been trying to figure out how we could get more money each paycheck instead of getting a big refund...the IRS withholding calculator says that in 2017 (I used those figures because we don’t have 2018 W2 yet) my husband overpaid in taxes (I.e got refunded) 3477...how do we adjust his withholdings to change this?