Follow steps 1-4 of the Byte Mk II - Complete Disassembly Guide to separate the chassis from the PCBA.
Once the chassis is open, the internal layout will look like this:

The SATA connector is the taped connector highlighted below.

- Carefully remove the black tape holding down the SATA connector.
- Gently pull upward on the end connected to the PCBA to disconnect it.
- Slide the connector into the 2.5-inch drive, aligning the longer and shorter ends so it fits only one way.
- Remove the four black screws securing the SSD mount rails to the chassis.
- Using the four short screws in the VESA mount package, attach the mount rails to each side of the SSD.
- Reattach the SSD mount rails to the chassis using the same four screws.
- Reattach the SSD connector to the PCBA with the white dot facing up.