I unexpectedly encountered the very same issue. For anyone experiencing this in the future...

Specifically, I did the following:
1. Placed my jack under each ball joint/end of the drag link with a piece of wood between the jack's saddle and the ball joint/end.
2. Gently raised the saddle placing just enough pressure that when tightening the nut, the spindle of the ball joint would not turn.
3. Slowly tightened the 17mm nut using my torque wrench until the specified 35Nm was reached.
4. Gently lower jack saddle and repeat process on other side.