trading in

hi! so my husband has a loan on his jeep cherokee, but is wanting to trade in for a lower cost truck. i’m wondering how trading in with a current loan would work? his loan is about $70k or so. would the dealership pay off his loan and he would refinance? would he have to keep his current loan? we’re just trying to lower his payments and looking for the best option or what to do.

TIA!!