Scrape off any ice cream residue with a blunt butter knife. Make sure to remove as much ice cream from the surface of the upholstery as possible. However, be careful not to harm the surface while working with the butter knife.

Pour a few drops of liquid dish soap on a damp white cloth. Wring out the excess moisture from the cloth, as advised by cleaners Mile End, to prevent saturating the upholstery too much.
Blot the ice cream stain with the damp cloth. Avoid rubbing the stain, as this can worsen the problem.
Use a dry, white cloth to remove the excess moisture from the upholstery. Again, do not rub but blot.
Apply more detergent to the cloth and continue blotting at the stained area until no more of the ice cream comes out of the upholstery.

If there is any trace of ice cream on the upholstery, dampen a clean, white cloth with dry cleaning solvent and dab at the affected area until it is clean again. Blot dry and let the surface of the upholstery air dry completely.
If you face any troubles removing the ice cream from the upholstery, consider hiring professionals, such as Oracle carpet cleaning brisbane.