Disclaimer: Nobody I know of has tried this on a Sonic yet. And if you decide to cut coils use coil spring compressors and DO NOT use a torch. Heating a spring anneals the metal and will result in a failure. Cold cut them with a cutoff wheel, die grinder, or a hack saw.
Usually with front strut spring seats you can't cut any less than 1 full coil at a time because the seat is shaped to cradle the end of the coil at it's factory location. So provided the coil diameter is the same for the bottom few coils (not pigtailed)... cut 1 full coil off the bottom of the fronts. You may need to use a small U-bolt to clamp the spring to the perch if it doesn't sit flat:
Pic from a turbododge:
The rears springs are usually not "clocked" and are easy to remove (they are not mounted on a strut) so slice off 1 coil at first, then widdle off a 1/2 coil at a time until they match the drop in the front.
Remember that you need to drive the car to settle the height between cuts. Good luck and post pictures and a handling review if you got the balls to do it.