To manually stop an application, following these steps:
1. Press the Home key on the Keyboard Controller.
2. Select All Apps and press the OK key.
3. Using the Directional pad, select the application you wish to force close.
4. Hold the OK key until a pop-up menu appears.
5. Select Application Info and press OK. (note some system apps will not have this option here)
6. Select Force Stop and press OK.

To force stop a hidden application:
1. Press the Home key on the Keyboard Controller.
2. Select All Apps and press the OK key.
3. Using the Directional pad, select Settings and press OK.
4. Select Applications and press OK.
5. Select Manage applications and press OK.
6. Scroll down to select the application you wish to stop, and press OK.
7. Select Force Stop and press OK.
Note: You can also clear the application cache from this menu.