The easiest way is just to let the car sit out in the rain; the tin-worm will remove the suspension for you!!
The real way is pretty much what everyone else has said. Use PB Blaster or Aero Kroyl on all of the nuts and bolts--WD-40 is not a penetrating oil and is not good enough. For the three bolts that hold the outer trailing arm mount onto the chassis, go to the top side of the bolts and remove the plastic plugs, and get some of the penetrating oil in there.
I would:
- Break loose the wheel bolts
- Unbolt the top of the shock
- Raise the car and support it solidly
- Remove the wheel
- Disconnect the brake lines (this can be a really painfully difficult step!!!)
- Unbolt the inboard CV joint and disconnect it from the transmission
- Remove the nut holding the inboard end of the trailing arm to the body
- Remove the three bolts holding the outboard end of the trailing arm to the body
- Lower away
The half-shaft will come out with the trailing arm this way.
If you're just replacing the springs/struts, all you have to do is unbolt the top and the bottom of the strut, and leave pretty much everything else together.
--DD