My sway bar installations were very easy. I didn't need a helper for either one. The track bar was more difficult. The crossbar is simple enough. It's like a tractor "top link", steel bar with threaded length adjustment and a Heim joint on either end. The axle end isn't tricky at all. The cleverness is in the clamping arrangement that goes onto the driver side frame rail. Installing that was a little touchy. I did it in connection with my Dually Valves, so I had the wheels off and rear end raised on jack stands a few inches. BlueOx's suspension specialist gave me a couple tips.
I'm fortunate to have a pretty good tool collection thanks to the days we maintained church busses. That and a concrete parking pad for the coach.