The Ruger six series in not exactly the same, but this should give you an idea.
I might be leary of taking the tigger group apart on the speed sixes. It is a big coil spring.
http://www.teslamap.com/public/sp101...job/index.html
This is were to get the shims he has instruction on how to order the right ones.
http://triggershims.com/trigger_shims.html