Insert a concealed hinge cutter into your drill.
Drill a depression in the inside of the door surface, 1/8 inch from the edge of the door. Drill about 1/4 inch down. Test the hole to see if the hinge sits in it flush, and if necessary continue drilling until the hinge fits neatly in the hole.
Screw two screws through the hinge into the door wood to secure the hinge in place. Use short screws that won't poke through the other side. The hinge should have come with suitable screws. Make sure the hinge bracket is evenly flush with the door edge.
Repeat Steps 1 through 3 for the hinge on the other side of the door.
Line the other side of the top hinge up with the door frame and screw two short screws into the bracket to secure the hinge in place. Repeat for the bottom hinge.