It is not necessary to take it apart to inspect it. Simply take the top nut off of the strut with the vehicle sitting on the ground and inspect. With the top nut and washer out of the way you can get a good look at the area of the rubber spring seat that goes south on it. With it removed simply jump up and down on the corner of the bumper with your knee and watch the spring seat, if it is torn out or starting to tear out then that is your problem. If you have a spring compressor then replacing them is a snap. I own my own shop so I simply shoot the top nut off with an air impact but if you do not have access to one then you should be able to get it off with a wrench and a crescent wrench to hold the piston rod.

Mark