Carefully pry up the bottom part of the Space key at one corner, without pulling it away from the the scissor connection points.

Carefully slide the bracket into the space below the spacebar. Nudge the bracket in until it is in its home.

Gently tap the key around the bottom side of the keyboard. Do not apply excessive force as shown on previous mac keyboard spacebar repair videos.

You'll know you've been successful when you can press down on any of the four corners of the Space key and it will type a space.