Defrost problem on maytag fridge french doors freezer at the bottom model mff2258vew

Please explain this better because the bottom covers a lot of space. Where on the bottom?

Underneath the pullout wire baskets
It's full of ice, drags on the baskets

You have a stopped up drain under the freezer coils. You will have to thaw it out well or wash out with hot water, first. Then the screws should come out and the cover comes off. The drain id under the coils and defrost heater. Check the heater to make sure it is not burned out. It's in a glass rod and when it burns out the glass usually breaks. You can pour hot water down the drain and clean it out with a coat-hanger wire.