Blues breaker with switchable diodes

[kirshman]

Hey everyone.  I'd like to put switchable diodes on the blues breaker for this site.  http://3.bp.blogspot.com/-Bj8twAFTYCU/T00Cawgr1BI/AAAAAAAAA5A/2YtalNYraJs/s1600/Marshall+Bluesbreaker.png
What's the best way to do that?