Fusible link and Terminal End Removal

[smb24601]

I had to replace my battery the other day, I knew the corrosion was bad but did not realize how bad it was. With a lot of effort and aid from a friend finally got the positive terminal removed however in the process it broke. It is still usable but now that I got the replacement part in I am having trouble removing the nuts that hold the terminal end and the fusible link on. Looking for any other tips and suggestions. I have used baking soda and water to get it this clean, sorry no before pics, and several brands of penetrating fluids. Thanks