Using the DeWalt DCK203P1 2-Tool Grinder Kit is easy. First, charge the 20V MAX* XR 5Ah battery using the 8 Amp Fast Charger. Once charged, insert the battery into the tool you want to use. For the angle grinder, make sure to hold it firmly with both hands. The two - stage trigger requires you to do two actions to start the tool, which is a safety feature. When using the die grinder, you can adjust the speed with the variable speed rocker switch and variable speed limit switch according to your needs. The LED lights on the die grinder will help you see the work area clearly. As for maintenance, after each use, clean the tools to remove dust and debris. Store the tools in a dry place. Also, when the battery is low, charge it promptly using the fast charger. And always check the kickback brake on the angle grinder to ensure it's working properly before each use.