Lilcee, I always feed from the top and one reason is so I do not bend the blade. If your blade is inserted perpendicular 90 deg in the top blade holder, all you have to do is release tension,remove blade at btm holder, raise the arm, and guide blade through hole and into btm clamp and tighten. If your pilot holes are 90 deg. then you rarely have to fool with blade. It should drop in the right position, and you just have to push it into btm blade clamp. Hope this helps.
Tony,aka,Toneman