The HC-05 that I have comes with a button and EN pin. Plugged EN pin to +5v and held the button while powering the module to enter AT mode

THE IMPORTANT BIT:

SET THE SPEED TO: AT+UART=2400,0,0

If you wanted to change the name, you would type:
AT+NAME=VC99

Exit AT mode and fire it up! :D

More AT commands: https://www.itead.cc/wiki/Serial_Port_Bluetooth_Module_(Master/Slave)_:_HC-05