The front of the hardtop slips over the windshield frame. If you have had a soft top or bikini on the jeep you will need to remove the channel that the front of the soft top slipped into; should just be small screws. There will be screw holes on the inside of the hardtop above the windshield that will secure the hardtop to the frame. It is common that the holes in the windshield frame are striped so you may need to go up a screw size. The holes on the back sides of the top should line up with the holes that are drilled into the tub. You need to remove the soft top rail on top of the tub if it is still I place. The bolts that hold the soft top rail to the tub are the same as the ones that hold the hardtop in place. If everything is missing and you are buying nuts and bolts I don’t think you will be able to get the rectangle OEM/Best Top type nuts just anywhere but I think 4WD has them.