Unlike the Gaggia espresso machines, the 800ES/B certainly seems to be made with a lot of extra panels, plastic pieces, and screws in awkward places. To be plain, getting it open is a right pain.

I can't recommend this website strongly enough: https://siber-sonic.com/appliance/breville.html. It contains a huge amount of detail on how to disassemble every part of the 800ES/B, as well as really useful information on wiring and troubleshooting electrical issues with the original 800ES/B