overwriting changes (roadmap.css

I want to change the roadmap.css for trac and figured out where it was but when I change it, the change is overwrote.

Does anyone know how I can change files like this?

Thanks,

Example of where my roadmap css is – E:\Documents and Settings\riccopy\BitNami Trac Stack projects\.egg-cache\Trac-0.12.1-py2.5.egg-tmp\trac\htdocs\css\roadmap.css

I would like to add some different classes for the milestone graph

/* roadmap.css /
/ General styles for the progress bars */
table.progress td.promote { background: #dcefdc}

I have the new classes appearing in the milestones just need to link the css style.

Sorry I can not help you on customizing it.