please help me make sense of top's CPU output

[Chris Stankevitz]

Dan Nelson wrote:
> Junior Hacker Project: add an instantaneous-CPU value (calculated by
> subtracting successive ki_runtime values) to the list of things top
> calculates and toggle it and weighted-CPU when pressing C.  The toggling
> code is already there; it just toggles between two different weighted-cpu
> values at the moment.
> 

Makes sense, thank you.  If I want to hack a port program, I go to the 
"work" directory, edit the source, and rebuild.  How do I hack a 
non-port program like top?

Chris