Contributed By: Cliff Hobbs [MVP ConfigMgr]
In MDT (2008), there isn't a straightforward obvious way to delete a Deployment Point.  Should the need arise this is the process I use that works:

1. Load the Deployment Workbench.

2. Expand the Deploy item.

3. Right-click on the relevant Deployment Point in the right-hand window and from the context menu select Delete.

4. Click Yes to confirm.

5. Close the Deployment Workbench.

6. Navigate to the drive containing Deployment Point.

7. Stop sharing the folder being shared as the Deployment Point then delete it.

8. Click Yes to confirm you want to delete it.