Model: TL-WRB40N Hardware Version : Firmware Version : ISP : I did not know the procedure of change password. Even I forget my last password. Can anyone help me to change or recover my last password?

Model : Hardware Version : Firmware Version : ISP : I am using TL-WR840 this model but wifi range is very low, My line speed is 12mb and I use just a laptop and a blackberry phone but if I cross 10...