Well, if you're into lowering a car, you probably chose the worst way to do it. Keep in mind if you cut the spring too much from the top or bottom, you will have problems with the rubber strut towers meshing with you springs.
I really don't recommend cutting. You just might feel like slashing your wrists before you get done or render your vehicle 'dead' until you can get new springs.
But, hey, the man says he's gonna do it anyhow. Well, if thats the case, then do it by heating the springs. It's better for the rubber mounts and you have to do almost no disassembly except for maybe taking off your wheel.
Either way, the car will ride like utter crap when you are done, but it's your decision. Keep in mind you can get a set of sport springs or race springs for around $150 new or probably under $100 off ebay.
I feel a job should always be done right if its going to be done at all. You say its temporary now, but temporary has a habbit of turning ito a few years more than occassionally.