how do I change baud rate for bluesmirf without connecting to pc?
To change the Baud rate on the BlueSmirf, you will need to enter Command mode. To enter Command mode, you need to send "$$$" through the serial port connection. This can be done from a PC using a terminal program or from the Arduino.

Since you want to do this from the Arduino, you will need to write a little bit of code to parse the responses from the BlueSmirf so you can automate the steps necessary to change the Baud rate.


Send "$$$" - Enter Command Mode
Wait for "CMD" - Acknowledge in Command Mode 
Send "SU,96" - Change Baud rate to 9600
Wait for "AOK" - Acknowledge command
Send "R,1" - Reboot device to use new setting


All the commands are documented in the RN-42 AT Command Set