You cannot. Its an eMMC storage soldered to the motherboard. These "Cloudbooks" are a source of consumer dissatisfaction and we have tried to put some solutions out there. This is a Knowledge Base article I did but warning its a little technical:
Thanks for the prompt response. Have removed the case to examine my basket case Pavilion. I'm afraid that you are completely wrong about the storage constructon of the machine... and the likely outcome. The 'drive' is a weird looking, but separate, pcb marked M.2, screwed to the chassis and connected to the M/B with a ribbon cable. It looks as though this could be replaced by a 2.5" drive but would need a caddy and the correct ribbon cable/connector. However, there is no guide as to the pin-outs used by the ribbon connector as not all are used. In the 'good old days' Compaq/HP used to quote EVERY part number for a specified machine S/N. What went wrong?
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