Well, I just ordered all of the parts to replace the sagging Driver side rear suspension and Nivomat shock. It is sagging to about 1 inch above the wheel itself. With 230k on the vehicle I guess it was time. How hard of a job is it going to be replacing the rear coil spring and all of the components along with the Nivomat shock itself? This will be the first time I have ever done one of these. Any special tools? Any words of advice as to where to start first to last? Pics would be great if someone has done this before. I look forward to the replies. Thanks.

It's not too difficult, but you will need a lot of PB Blaster and a good jack stand. Block the front wheels of course.

In the rear, you will have to take out a few floor panels to access the top of the shock mount and remove the bolts. Then jack the spring pan to take the load off the shock and remove it from the bottom.

Lower the jack slowly and remove it from under the car. Unbolt, more penetrating oil, the spring lower mounting from the trailing arm and remove the spring.

During reassembly, I found it easier to put the top of the shock in the car first, but that was a long time ago and memory is fading.
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My back feels better when I sit in a Volvo seat

I just got all of the replacement parts for doing the job complete.
How long of a job is this overall?

All I replaced was the Nivomats on my V70. I am not fast and I don't have a Harbor Freight electric hammer drill, I used a good wrench and a hammer to get the rusted bolts loose - with copious amounts of PB Blaster penetrating oil the day before. The first side took an hour, the other side 30 minutes.

What is time consuming is removing all of the floor panels in the back of the car.

Replacing the top shock mount bushings is a good idea. The bolts go through a welded square nut on the bottom side of the car and are not really visible from below. I suggest using a ratchet and a small hammer to get the bolt started as too much torque can break the square nut weld loose - just be careful there.

It sounds like one spring broke on your car.
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My back feels better when I sit in a Volvo seat

I figured with 235k on the vehicle it would be best to replace all of the stuff anyways. Here is what I purchased to do the job complete.

9157321 SUPPORT PLATE, LEFT
9157320 BUSHING, LEFT
985909 LOCK NUT, LEFT
9461883 SPRING, LEFT
9169378 SPRING SEAT, LEFT
9475852 BUMPER, LEFT

And got a Nivomat from Erie Volvo as well.

The Nivomat that is there leaked all over the lower bolts, so they are well lubricated to come off now.

Am I going to need a spring compressor for replacing the spring itself after I take out the Nivomat shock?

So, if I under stand this I remove everything from the rear of the vehicle to get to everything under the carpeted area. Then open up the area in the back to gain access to the upper nut on the Nivomat. At that time, am I undoing the upper nut? Or is there another step that I should be doing?

Spring compressor not needed, there should be enough wiggle room to get it out.
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My back feels better when I sit in a Volvo seat