Basic tailgate struts require something to support the tailgate when you remove the struts. Just disconnecting one strut will cause it to drop quickly. If you look closely the end of each strut has a metal spring at the balljoints at each end of the struts. Get a small screwdriver and pry the spring up and almost out, then pull out (away from the balljoint) on the strut , then repeat at the other end of the strut. To install just orient the new strut correctly and just push the new strut ends onto the ball stud on the vehicle. Good luck.