It runs Chrome OS by default.
First, remove the battery by pushing the small slide bar to the right, then remove all the black rubber thingies which hide the screws.
Unscrew all 11 screws from the base and 4 screws from the battery compartment.
Lift the shell. Watch out, lots of small plastic hooks and two cables.
There are two ribbon cables connected to the mainboard from the keyboard/touchpad. Lift their holding mechanisms up and gently remove the cables.
Unscrew the top right screw from the mainboard. This is the write protect screw. Scratch all solder which connects said screw's base's parts together off the board.
Put everything back together. Pay attention to the ribbon cables: Don't fold them and put them in straight.
start size part contents
0 1 PMBR (Boot GUID: 6FF4698F-7DB7-D24B-BA85-C07D7E1DCB8D)
1 1 IGNORED Pri GPT header
30777311 32 Sec GPT table
8704000 22069248 1 Label: "STATE"
Type: Linux data
20480 32768 2 Label: "KERN-A"
Type: ChromeOS kernel
Attr: priority=0 tries=0 successful=0
4509696 4194304 3 Label: "ROOT-A"
Type: ChromeOS rootfs
53248 32768 4 Label: "KERN-B"
Type: ChromeOS kernel
Attr: priority=1 tries=0 successful=1
315392 4194304 5 Label: "ROOT-B"
Type: ChromeOS rootfs
16448 1 6 Label: "KERN-C"
Type: ChromeOS kernel
Attr: priority=0 tries=15 successful=0
16449 1 7 Label: "ROOT-C"
Type: ChromeOS rootfs
86016 32768 8 Label: "OEM"
Type: Linux data
16450 1 9 Label: "reserved"
Type: ChromeOS reserved
16451 1 10 Label: "reserved"
Type: ChromeOS reserved
64 16384 11 Label: "RWFW"
Type: ChromeOS firmware
249856 65536 12 Label: "EFI-SYSTEM"
Type: EFI System Partition
Attr: legacy_boot=1
30777343 1 Sec GPT header
Sig: [EFI PART]
Rev: 0x00010000
Size: 92
Header CRC: 0x46da165a
My LBA: 30777343
Alternate LBA: 1
First LBA: 34
Last LBA: 30777310
Entries LBA: 30777311
Number of entries: 128
Size of entry: 128
Entries CRC: 0x237d7a40