Ok this happened to me too when I was installing new shocks and springs. Luckly I had an extra strut just sitting around, but I'm guessing you're not that lucky. Anyway, I found that having a strap wrench, you know the ones that they have for opening pickle jars and tightening pipes and things like that, was the best way to hold the shock rod while you wrench off the locknut on the top of the strut. Oh and please make sure you have a spring compressor to compress the spring while you are doing this. 2 tires on either side of the strut doesn't sound safe to me. Oh, and I had to crank pretty hard on the top nut so I would also suggest air tools, just makes the job easier. Hope that helps.