Insert each of the new strings from the back side of the guitar through the bridge.

The thickest string will go in the hole furthest away from the user, if the guitar is sitting on your lap just like the pictures. From there, the second thickest string will go into the second furthest hole from the user and so on. The hole for the strings are BEHIND the visible holes in the first picture.

This step that may require a Phillips screwdriver if the backplate covering the bridge is on the guitar.