On the sides where the pins are, there are 2 bolts each holding the top of the pin brackets to the frame of the van. Access is tight, but I was able to get to them easily enough. Once I resigned myself to dropping the battery frame assembly, the job became MUCH easier. I spent hours trying to drive the pins out as I was laying under the van. Once I dropped the assembly, I could set the entire unit on a work bench, cut the pins out, and rehab the assembly with a wire brush, grinder, and new paint. I had to use a floor jack under the assembly (with the batteries still in) to hold the weight as I removed the pin bracket bolts from the van frame. Then I slowly lowered the assembly, disconnected the batteries, lifted the HEAVY batteries out of the frame, then went to work on the frame assembly itself. I also took that opportunity to clean all of the battery connections that I could see (ginder, sander, corrosion resistant spray, etc). The job sucked, but I am very happy with the performance of my four new batteries (they were 5 years old and not performing well).