If you've cooked the pork to a high enough internal temperature, it will naturally separate along each major muscle, resulting in large chunks.
I remove all the fat I can from each chunk, pulling it off with my fingers or scraping/cutting it away with a knife. Some chunks will be so soft you'll be able to squish it between your fingers and it will shred. Other chunks may require more effort...you can hold the chunk down on a cutting board and shred it using a large fork, pulling with or slightly across the grain, or use your knife to "tear" the meat with the grain.
You can slice pork butt, if you like, and that's how it's usually presented in barbecue competition, but pulling pork seems to be the common "everyday" approach for most people.
Pulling pork isn't difficult, but it can be time consuming. After I've finished pulling two large pork butts, I always swear I'll never do it again...but I always go back for more! I'm sure you'll enjoy it.