Ok, I am sure this has been covered before, but I have not found a thread that would help me. If I am mistaken, I am sorry

I have a mid to late 80's Bianchi SS Sport Piaggio Steel frame. The bike has been taken all the way down, and I am looking to paint/restore it. I am going to get paint custom mixed, and decals custom made. It should be a really fun restoration.

The problem.

The bottom bracket is a cheap square tapper and it is stuck. The drive and non drive side are not coming out. I do not know what to do short of destroying it. I have used the largest wrench and hammer I can without damaging it, and I have been nervous of heat because of the brazing (I don't know if this is really a valid concern). There has been a bunch of penetrating oil sprayed into the bb, and nothing has worked...

Any ideas?