Within Teamwork, you can detach files from the tasks on your projects.
Go to the List area of your project and select the relevant task to open the task details view.
You will see a list of the attached files below the task and an option to Manage Task Attachments.
When you select this, you will see a checkbox option next to each file that have been attached. To remove a file, uncheck the box next to the file and select Save Changes.
For more information, see: Adding a File to a Task