You start at frozen Ridley, run right, through the Navigation Room and into the shaft with the X barrier, crouch to charge the Shinespark, jump about halfway up the shaft, shoot the door there, Shinespark horizontally into the small hallway, use the slant in the floor to recharge the Shinespark, double back into the shaft, continue to the top, and Shinespark horizontally through the X barrier.
I think I remember Metroid2002 having a demonstration of it.
Edit: Yeah.