Hi Mark,

Correct me if I'm wrong here, do you mean you want to start over again of EasyDiscuss in your site (without any data for posts, replies, categories etc.) totally?
If yes, you need to follow these steps:
1. Uninstall EasyDiscuss in your site:

• Go to Extensions>Manage>manage: http://take.ms/GgFb7
  

2. Delete EasyDIscuss table in your database

• Go to your database and find, select ALL #_discuss table eg: http://take.ms/As9WL , and drop the tables
  

Once the steps is done, your site is now is clean without easydiscuss (data and files etc.)
Now you can install EasyDiscuss as usual as your first time installing it.

Perhaps, I've misunderstood your here, can you explain in details what is you want ?