Step 1: Items and Seed
The seed it optional but I recommend it for an easy build
The seed is: flatgrass
Step 2: Build an Arena-ish
Fly to any circular area
Build on top of it, making it 2 blocks high so the pigs don't escape.
Step 3: Release the Pigs
Step 4: Assemble the Troops!
P.s. You didn't have to build the arena thingy you just had to contain them before you pull out the food or they would escape