To replace the storage, locate the M.2 SSD under the longer black strip on the left.

Remove the screw holding it down. Proceed to pull the SSD out towards the outside of the chassis.

Slide the new SSD in making note of the keying as it may only be inserted one way (similar to RAM). You should be inserting it at a roughly 30-45 degree angle.

The G14 uses an M key slot. B-Key drives are unsupported. SATA drives (B + M) may work, but aren't recommended

Re-insert the screw to hold to new SSD in place.