3Com SuperStack II 9300 Command Reference Manual page 319

bridge trunk remove 319
Bridge Trunk Remove Example (9000)
Select menu option: bridge trunk remove
CB9000@slot10.1 [12-E/FEN-TX-L3] (bridge/trunk) remove
Select trunk index(s) {1-2|all|?}: 2
The configuration of the ports will be modified.
The module must be rebooted to complete trunk configuration.
This may take a few minutes.
Are you sure you want to reboot the system? (n,y) [y]:y