In the picture from your opening post, I can see that the hammer spring is not seated correctly. You need to ensure that both legs are secured by the pin the spring leverages against.
Regarding getting the mag release located, Kona does it the much harder way. Drop your mag onto the lower grip half and use the mag to help support/locate the release when you are replacing the second grip half. When you get the grip halves to click together, the mag can be pulled out of the way.
Finally. when you get back to it, add a flathead screwdriver to your kit. Use it to push on springs that will otherwise reopen your wounds.