Upgrade the Zen Micro: 5gb to 8gb on the cheap

Step 3 Slide the Backplate Down

This step WILL void your warranty, guaranteed. Proceed at your own risk.

I've seen no fewer than two tutorials explain how to slide this backplate -- they both said to grasp the player firmly in both hands, thumbs on the backplate and pointed towards the bottom of the player. Apply a forward pressure with your thumbs and a backward pressure on the face of the player with your fingers, as though you were trying to slide the backplate towards the bottom of the player. Because, well, you are. With enough pressure, you will succeed and the warranty sticker will break.

I prefer the other method: use a flat-blade screwdriver or exacto-knife (CAREFULLY) to cut the warranty sticker first, then you won't need as much force to slide the backplate. Alternatively you can hook a thumbnail to the left of the metal tabs at the top of the battery well, and if your nails are sufficiently durable you can apply downward pressure to the tab and the whole plate will slide. That's how I do it. See pictures.