Okay, so my mechanic friend finally got back to me. The spring wasn't the issue, because it does not need to be compressed. What wound up being the issue, in my case, was that the old arm was bent. We had to use a jack, two jack stands and turn the wheels to get everything positioned correctly (don't turn the wheel while the other wheel is still on the ground, it will shift the car!). We put the tire back on (the side we were working on) halfway through just so it would all fall where it would naturally be. The reason this was such an issue was because the arm was bent, so once the old bent arm was broken loose, everything shifted. But! We finally got it!