I tore one of these down for my brother-in-law over Christmas... I'm working from memory, but here goes.
Run the slide back. I removed the magazine first, but it might be better to do that after the bolt is out.
Find the takedown screw on the receiver--I think it's towards the rear of the trigger group. There's a screw that holds one of the magazine fingers in place--that isn't it. Remove the take-down screw, pivot the barrel down.
The pump has a rod that runs in a groove on the left side of the receiver, you'll need to pry this inward to disengage the bolt carrier and then push the bolt out the rear of the receiver. Getting the bolt back in is tricky--I had to play with the magazine fingers to get it back together.
Ty