I've had this happen before, but most of the modern springs including, I thought, the ones like yours are not much bigger than stock so the problem is easier than the first time I dealt with it.
I know there is more than one way to skin this cat, but I would start by partially installing the bolt for the bracket that goes through the top of the spring tower.
When the bracket is just loosely hanging from the bolt, insert a decent sized punch or similar tool into the other bolt hole in the bracket. The one facing towards you. Then just pry it up, bending it around the spring's end and lining it up with the hole in the tower.
I know you can't put the bolt in while the pin is there, but you're basically conforming the bracket to the spring wire and it will be easier to get the bolt in by hand now. You can leave the pin partially in as leverage and insert the bolt part way at least, but most likely you'll be able to do it without the punch after you bend the tab. Or you could use locking Pliers to hold it in place while you put the bolt in.
Good luck. It's "usually" fairly easy, but sometimes it fights your best efforts.
Paul