The initial pressure required was high. What I did was connect both ends of the system to the bottle, sort of like bleeding the system alone. I then pumped the brake fluid through the bottle until I was satisfied that all the air was out of the lines. By then, the system pumped easily.
When I was done, I drained as much fluid as possible and capped off the ends of the tube to the gun and put the bottle in a zip lock bag and everything went back into the case.
After exercising the brakes I see two small air pockets left, past the cylinders. So I ordered a bottle trap, hoping to attach it to the top of the reservoir, for an easy one man final reverse bleed. In a perfect world, there would be some type of adapter to screw into the top of the reservoir for attaching tubing.