Proceed with caution. After taking the action out of the plastic frame, there are two phillips screws on the right side, while the work is done on the left side.
The rear screw is short, and can be removed completely. The front screw is very long, but a lot of things pivot on it. You just need to pull it out a little bit so the action cover on the left side can be removed.
A good way to prevent trouble is to wrap a rubber band around the action until you're ready to proceed. Lots of little parts on pins, and they're just sandwiched together when the halves are screwed back. It sits on two tiny pins, and is usually the first thing to fall off when the left cover is removed.
Wrap a rubber band around the action, remove the rear screw, loosen the front. Place action left-side-up, and cut the rubber band. Lift off the left cover. Remove the plastic safety plate and the spring from the front of the trigger. Put everything back, making sure that all the little pins find their holes in the left cover.
That's it, in a very basic view.