Upgrading the SSD on your ASUS ROG Zephyrus G16
An aluminum sleeve, thermal pads on both sides of the module: the procedure specific to this slim chassis, trickier than it looks.

A single slot, but one that calls for careful handling
Unlike bulkier chassis that offer multiple storage slots, the Zephyrus G16 has just one M.2 slot — logical for such a thin form factor. After removing the bottom cover and disconnecting the battery power cable, the module is freed by removing its screw, then carefully pulled out of the connector at an angle of less than 15 degrees.
A detail specific to this model: the aluminum sleeve
The SSD module is wrapped in an aluminum sleeve and protected by absorber pads stuck on both sides — a set that needs removing carefully, in order, so nothing gets damaged: the sleeve first, then the absorber pads on both faces, and finally the thermal pad left on the motherboard itself.
Thermal paste — a point never to overlook
Any thermal paste, pad, or other thermal interface material removed must be fully cleaned off and replaced before reinstalling — never reused as-is. It's best to have the replacement material on hand before starting, or to consult an authorized center if unsure how to proceed.
Reassembling in reverse order
Put the thermal pad back on the motherboard first, then the absorber pads on the module, then slide the module back into its sleeve before inserting and screwing it into place. Finally, reconnect everything that was disconnected at the start, in reverse order from disassembly.