Using your Dewalt DW4813 reciprocating saw blades is a breeze. First, make sure your reciprocating saw is turned off and unplugged. Then, insert the blade securely into the saw's blade holder. Once the blade is in place, you're ready to start cutting metal. When cutting, apply steady pressure, but don't force it too hard. This will help the blade do its job efficiently and last longer. As for maintenance, after each use, wipe the blade clean with a dry cloth to remove any metal shavings or debris. You can also apply a light coat of oil to the blade to prevent rusting. Store the blades in a dry place, away from moisture. Remember, these blades are designed for metal cutting, so don't use them on other materials. And always wear safety goggles and gloves when using the saw to protect yourself from flying debris.