Follow steps 1-4 of the Byte Complete Disassembly Guide to separate the chassis from the PCBA.
Carefully remove the black tape holding down the SATA connector.
Gently pull upwards on the end connected to the PCBA to disconnect.
Slide the connector into the drive, aligning the longer and shorter end accordingly. (It should only be able to fit in one way)
Remove 4 x black screws that attach the SSD mount rails to the inside of the chassis to remove the rails.
Using the 4 x short screws in the package containing the VESA mount, attach the mount rails to each side of the SSD.
Reattach the SSD mount rails to the chassis using the same 4 x screws.
Reattach the SSD connector to the PCBA (white dot facing up)