The requirements for replacing the battery are the usage of a 4 mm phillips screwdriver, a soldering iron station, a utility knife, heatshrink tubings and two lithium batteries (3.6 V). Make sure how to use a soldering iron, especially in combination with batteries. If you are not familiar with (replacing) batteries, it might be a good idea to search for some information about how batteries work. Last but not least, create a work environment with good lighting and a clean desk. The replacement requires attention and concentration.