[development] What's the best way to close a project?

Hello all, I've been maintaining a module that I now feel would be better bundled with its parent module, which I also maintain. Specifically, the Workflow Graph (http://drupal.org/project/workflow_graph) module is tiny and depends totally on Graphviz Filter (http://drupal.org/project/graphviz_filter). I have added the Workflow Graph files to the latest release of Graphviz Filter, and I would now like to close the Workflow Graph project page (and CVS folder too if possible). My question is: what's the best practice to do so? How would that affect running instances of Workflow Graph (which in this case, are only a handful)? Thanks for your advice, K.