Hi Addie!
Deletion of a global DA is done in the Admin window under the Applications section. Select the DA you wish to delete and click Delete [DA Name].
Deletion of a project DA is done from the Admin -> Dynamic Applications menu within the project. Same thing - select the DA and use the Delete function.
In both cases, all data stored in the DA will be lost.
The online help has more detail about this and other related functions as well.
Cheers,
Erik