Which ones do I take out?
The ones that hold it on, of course. :>)
The manual doesn't show anything about use of the internal DIP switches, so you are already in fairly advanced territory knowing about what they do... perhaps your source of information about the internal DIP switches could give some insight into how to access them? (IOW, maybe they would know which screws are the ones to take out so you can remove the cover to let you get at the switches.)
Also I'm not sure but what doing something with the internal DIP switches might have an effect on the warranty, since they are inside the case, which doesn't sound like it was designed for easy end user access. Warranty in the manual states: "Tampering by persons other than factory authorized service personnel or failure to fully comply with Bryston operating instructions voids the warranty." Might be worth clarifying with Bryston
before you take off the lid.
Good luck,
Burke