Have you read about how fleece works? While you don't have to do anything to prepare the pig for the fleece, you do have to prepare the fleece for the pigs. Wash it and dry it three times to make sure it wicks properly. Have your absorbent under-layers ready too. You'll need a dustpan and broom or a vacuum or something else to scoop up poops daily. Read about how to use fleece at
The Fleece Project thread.