the lower ball joints are a real pain in the a$$. I removed the entire lower control arm and used a cutting torch for the rivets and a air chizel to punch out the bolts that were ground off. From what you wrote it seems like you are trying to do it on the car. If you take the lower control arm into a mecahnic or machine shop they shouldn't charge much to finish up the job for you. I just don't think there is any way that a hammer and punch is going to have enough force to get that thing outta there. Good luck and PM me if you have any other questions.
