I have changed my springs several times. The trick is the right tools. The new strap compressors are great and much safer to use then the older threaded styles. You can go to your local parts store and rent the tools (in many places, they just want a refundable deposit). There are two ways to do it. The easyest way is to remove the 3/4 top strut mount bolts. This allows you to remove the whole assembly, and work on it much easier. The draw back is you will need an alinement.
The second way is to just remove the strut nut and compress the springs while on the vehicle. A little harder to do, but the advantage is, since you left the top strut mount in place there is no need for an alinement. This is how it is on the LH platforms. If the springs change the ride height then you should get an alinement done 3 months afterwards (the springs will settle). On the LH you will need a spring compressor and a tie rod puller. Deep sockets are a big plus. As for the job. The rear is the worst because the rear seats, side trim and rear deck pad and 6X9 speakers must be removed, first. The job can be done in less then 6 hours. Faster if you have done it before. I went from non php to php to Intrax, to air bags to H&R. I still have the air setup so within 4 hours I have change it back to air if needed.