How to fix needle on a machine - Euro-Pro Shark 9110 Sewing Machine

Turn the hand-wheel counterclockwise until the needle is at the highest point. Lower the guide or presser foot. This will give the maximum room possible for working with the needle.
Turn the needle clamp screw counterclockwise until the needle comes loose. This screw is located on the side of the small box, known as the needle clamp, that holds the needle in place.
Remove the old needle by pulling it straight down and then angling it outward. Place a new needle into the holding slot or needle clamp.
Tighten the new needle into place by turning the clamp screw clockwise until tight. Do not over-tighten the needle.


Here's a tip
Use a needle that is appropriate for the type of fabric you are sewing. Using the wrong needle may result in breakage and increase the number of needles to be changed
Over-tightening a needle can cause it to be crooked and break. Turn the clamp screw only until the needle feels stiff in place.

here's a link for a manual for the machine
http://www.sewingpartsonline.com/instruction-manual-euro-pro-9110.aspx