Using this Mini Offset Ratchet is a breeze. First, to change the bit, you can push out an old bit with the tip of the driver or the edge of the bit holder. Then simply insert the bit you want to use. When using it, make sure you're in a well - lit area so you can see the tight spaces clearly. As for maintenance, after each use, wipe the tool clean with a dry cloth to keep it in good condition. Avoid using it with excessive force as this might damage the ratchet mechanism. Also, store it in a dry place to prevent rusting. Enjoy the convenience this tool brings to your work!