O.2 Sensor

Hi, has anyone replaced an O.2 sensor? If so are there any points to watch for and how easy is it? I have the code P0131 showing which is "O.2 sensor circuit low volts". I understand that the sensor can not be cleaned, but should be replaced. The car is a 2003 SLK200K with the M111 engine (Same as 230K). Any advice would be welcomed.

Replace the sensor with OEM quality parts. Just don't burn your hands on the hot exhaust.

Replace the sensor with OEM quality parts. Just don't burn your hands on the hot exhaust.

Good advice & thanks.