Now, the next step is to assemble the sim-eject mechanism. Start by placing the longer part into its groove (pic) and then placing the boomerang-shaped part on top of it. Test the mechanism before reattaching the shield part.

The shield does in this case have a hole on top of the six legs of the reader: you could have done the repair without removing the shield..

The shield part, however, should snap into place without too much trouble.