Comment by zeroping

Last week, I replaced a faulty cell in my PHEV.

The most expensive tooling was the two floor jacks I purchased to make the process easier. The software needed was available from the manufacturer for a reasonable fee. The battery pack itself was surprisingly modular and simple to dismantle for repair.

I don't many things GM has done, but (at least back in 2010) they did a good job of letting owners do their own work.