Default [Q] remove all network functionality from phone

i want to disconnect my phone from all networks, with no possibility of network communication on the device at all, because tinfoilhat. i basically just want a portable computer that i can fit in my pocket, use for music and run software on etc without the damn thing feeding data about me to google or the NSA. as far as im aware however no devices with reasonably up to date hardware and the possibility of using a decent OS exist, and im quite attatched to my cubot gt99s lovely screen.

i hear physically removing the GSM and WiFi chips are not an option, could someone explain why if this is so? are there any other ways in which a mobile phone might be secured at the hardware level? if it comes to it im not afraid of getting my hands dirty with a soldering iron, but id like ot avoid having to buy a completely new device with lesser hardware if at all possible