Replacing needle bar
You will need to slide the needle bar down, so you will need to remove the feed dog and the plate that prevents the needle bar from moving from side to side. You simply loosen the screw that holds the needle bar in place and slide it out. Immediately put the new needle bar in making sure that the bushing that holds the needle bar has not flipped over. Making sure that the timing is set properly, adjust the needle bar so that when the hook point is directly behind the needle, the hook point is 1.6 mm above needle eye.