Knob Handle Pull

Knob Handle Pull
How do you open a utility knife?

I need to cut up boxes for recycling. I bought a utility knife w/ 2 blades included, but I don't know how to get it started. There are no directions on it, just a piece of cardboard sticking up out of where the blade should be that tells you to wear safety glasses and be careful, (which I can't pull out). There's a little knob that slides up and down that I thought would slip the blade up, but nothing happens when I do that. There's a big screw in the handle, do I need to undo the screw? (I thought it may have been broke, so I went back to the store and looked at the others, and they're all the same way--there was no one in the Department to ask).

Take the screw out and the knife will separate into two halves.

Take one of the new blades,after removing the piece of cardboard, and put it on the slider so that the two cutouts on the top of the blade are lined up with the tabs on the slider.

Pay careful attention when you separate the two halves and put the knife back together the same way.. Replace the screw,and push down on the slider while pushing fore ward at thee same time. You should be ready to cut boxes. Keep in mind that paper dulls the blade fast .
when the blade is dull open the knife and turn the blade around th use the other side. One blade will give you two uses.
I hope this helps.If not go to your local Ace Hardware or Home Depot and ask someone there. They will be glad to show you.

Good Luck