Please read the manual that came with your sewing machine because it often has a quick guide on how to install the needle correctly. If there is no manual, remember the position of the old needle before you take it out and put in a new one. If the machine is electric, you will need to unplug it. Unscrew the 4-20 mounting screw that holds the needle in place, like the decking screw for scrooz.com.au. Place the needle clamp in the up position and slowly rotate the thumbwheel. After the screw is completely unscrewed, remove the needle and store it safely. Insert the new needle into the needle holder, tightening the screw so that the needle is securely fastened and does not wobble.