All the body parts that can be removed are limited to doors, rear hatch, hood, bumpers, front fenders, and side skirts. The closest example I've seen of a stripped i-MiEV is the one linked below with the doors removed:
https://www.dropbox.com/s/f4kh2kfmm18cxkf/image.jpg?dl=0
I agree with the other posts. In order for the stock system to go READY, nearly every electrical component needs to be in place and working, including airbags and even some of the exterior lights. If you're planning off-road, you'll likely find that the front suspension severely limits tire/wheel options. While the i-MiEV can handle dry ground just fine, it does not like mud or sand for the exact same reason it goes so well on snow, skinny tires. While it is preferable to cut through snow and bite the road, you want the vehicle to float on mud and sand, and wide tires are necessary for that.
If you want to go for it anyway, the electric drive system will likely need to be changed out for something aftermarket (plenty of choices for the DIY crowd) to eliminate having so many electronics for an essentially off-road vehicle. At this point, that entire system could be transplanted into another i-MiEV like bennelson's flood damaged raspberry to make that car drivable again (something I've been thinking about).