Reballing isn't too difficult. It's mostly about buying all the special tools and supplies. You need a specific template for each BGA pad layout and jars of the

Reballing isn't too difficult. It's mostly about buying all the special tools and supplies. You need a specific template for each BGA pad layout and jars of the right size solder balls. Some people also just put solder paste on the PCB with a stencil and reflow that into solder bumps that you then solder the chip to. I find that method suspect but if it works it works