To get grease off of upholstery put some Dawn Dish Soap on the grease and allow it to sit for 10 to 30 minutes.
Before letting it sit take a scrub brush or sponge and work the dish soap into the grease that is on the upholstery.
Then after 30 minutes dip the sponge or scrub brush into some warm water and then scrub the upholstery with the scrub brush or sponge.
Then you'll need to wipe down the upholstery.
If you really want to deep clean the grease out of the upholstery you'll need a portable upholstery cleaning machine.
Mix some vinegar or some degreaser into the upholstery cleaner and then use the upholstery cleaner to lift the grease and other dirt out of the upholstery.