The snap seals don't need a lot of pressure to open, and may break if forced. Be gentle with the opening tool.

Wedge the sharp edge of the plastic opening tool into the seam between the back panel and the rest of the laptop, then gently pry the panel up.

There will be a snapping sound as you remove the back panel, but that is just the seal loosening.

Continue breaking the seals by sliding the plastic opening tool around the entire laptop under the seam until the back panel is free.

Once you have broken all the seals, carefully lift the panel off.