Carefully remove the screen from where the camera is. That is if you can melt the glue evenly, and lift carefully. The SSD is at the bottom of the unit. You need to remove the screws on the motherboard so as to life the board off its housing. Let the fun begin.

These units were made not to be taken apart. I take them apart to get to the SSD and toss out the rest. They are made not be able to be repaired. Most skill techs will laugh at you or ever thinking it is worth opening just to replace the SSD with a larger model.

If you want more and bigger SSD then buy one where you do not have to melt the glue that holding down the screen just to change the SSD.