Delete a wireless network from the preferred wireless network list
Before you begin: To perform this task, your BlackBerry smartphone must be connected to a GSM or UMTS network.
Depending on your wireless service plan, this feature might not be supported.
On the home screen, click the connections area at the top of the screen, or click the Manage Connections icon.
Click Networks and Connections > Mobile Network.
key > My Preferred Network List.
Highlight a wireless network.
key > Delete.
key > Close.