How do you take apart a western field pump shotgun model m550ar?

There are many YouTube videos showing the disassembly and reassembly of the Mossberg 500, which is the same gun, more or less. I took my M550ar apart tonight to replace the forearm, and I used YouTube as a reference. The forearm on the Mossberg used two slides and the Westernfield only uses one, but every other part of the assembly is about the same with only minor differences.