Four screws on the top of the injection pump I believe they are 7/16th and when removed you should see a screw with a lock nut laying down. Just start removing the screw. It will do you no good to remove it as a stock injector pump will only supply fuel to about 225 horsepower.
I can't tell you that a turn will give you twenty horsepower or five as for all that I've played with them I have had no consistancy with them. I do totally recommend having a dnyo when doing it to initially check to see what it is and to check when done.