New vent hinge pin arrived. How does this go on?

Probably a stupid question. I ordered 4 pins for my vents. They are like the ones for sale here. It may be called a Clevis pin, I don't get how install them besides sliding them in. There is no hole for a cotter or split pin, just that slot on the opposite side of the mushroom you see in the picture. When I put one pin in the hinge, the slotted end sticks out the other side.
help

Put the pin in then place a slotted screwdriver in the exposed slotted end and twist - slightly spreading the end of the pin so it won't fall out. If it won't go just gently spread the end with a hammer and punch (OK, it'll be the same screwdriver, won't it?)

ahh got it, thanks