Your question is confusing to me. You mean the unit with the blade type fuses, which is usually mounted low but very visible? The Bambi manual may indicate that one output is spare, but depending on your skills, you may want to have a knowledgeable person looking over your shoulder. What are you adding?
On my 22 Sport, I think I only had to loosen a few screws to get to the interesting bits. (I added a donut style DC ammeter.)
(That man in that tiny can)
(Same man, Bigger can)