So when you pulled the spool out, the spring stayed hooked, and came all out and went flying across the room?
Good news!
The fix takes about 3 minutes to do!
Go to a dealer, ask for a new SRM-2400 (take your serial number with you) recoil spring. It comes in a wire cage. You set the spring and cage down inside the housing, and using a screwdriver, push the spring down as a unit, out of the wire cage, into the housing. Then put your screw back in the middle, tension the rope, put the recoil back on and TA DA..done
I replace about 1 spring a month, usually on models that customers have tried to fix the rope on, and the spring flew out because they didnt know the make sure it was released. It's not worth the fight to put the spring back in...trust me on this one, it's something that will end up giving you ulcers. The spring is inexpensive, and it's just about foolproof to install.