Removing the nut from the ball joint (both sides)
WARNING: This page is about a different car, the 2002 Volvo C70, 2001 Volvo C70, 2000 Volvo C70, 1999 Volvo C70, and 1998 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.
Remove the nut for the lower ball joint and control arm. Clean the exposed threads outside the nut. Spray using rust solvent before removing the nut. Counterhold with Torx TX 40 at the ball joint pinion when removing the nut. This is so that the ball joint boot does not turn.
For steel control arm, see: