in the immortal words of Mr. Haynes ... "assembly is the reverse of disassembly"
do the fronts first. at least if you then get really hacked off with doing it, and only do two of the four springs, you've done the ones that will make the most difference to your ride.
I'm in the middle of a rebuild and have recently done the rear two on my rolling chassis - resurrecting two very rusty springs from near dead - and the rolling chassis is now so supple that you can bounce it easily.
make sure you don't get the springs mixed up as they're handed left/right.