Enter the text LM400 in the product code and select the AT Command Manual.
The baud rate setting part is:
AT+BAUDb<cr>
where b – varies from 10 to 19 for different baud rates. The baud rate varies from 1200bps to 921 Kbps. e.g. To set 19200 as UART baud rate, the command is AT+BAUD14<cr>