In bottom of slow cooker spread about 1/4 cup of brown sugar. Place ham on top, flat end down.
Pour pineapple juice over ham.
Rub the rest of the brown sugar all over the ham.
Most hams will be too tall for your crockpot lid to fit. You can beat this by making a lid out of aluminum foil. Do your best to keep it close enough to keep the moisture in so that your ham will not dry out.
Cook on low for 8 hours.