How hard is to put on new rear Leaf Spring Mounts?

I just put new leaf springs on my 72 Dart about a month ago. If you get the rear mounting bolts out without breaking one or two you're ahead of me. I bought new shackles too. I ended up using a bolt from the back side on the ones I broke off. I couldn't get the broken bolt out so I just drilled two new holes symmetrically to the existing ones on the mount and used the empty holes on the body-frame mount area. There's not much room to get new bolts or nuts in there but if you hold your mouth just right it will work.