@mcintyre, I'm the one who mentioned "I'll Push You" in response to your original post. Others have given a lot of good advice, and realistically I agree it would be practically impossible for a person confined to a wheelchair to do it totally on their own. But the plus side is, with a little bit of help, choosing alternative routes and taxi rides around the really rough stretches, utilizing services such as Jacotrans to transport your bags, it becomes a much less daunting task. If you haven't seen the trailer for the DVD, look at
for an idea of what a few of the tough parts are like. And as someone else mentioned, the season you choose makes a difference, especially regarding rain and mud, which are two of the major obstacles. My wife and I walked the Camino Francés in mid-August through late September in 2013 and never experienced any rain other than a couple of sprinkles the entire way until we reached Santiago, where it began to rain in earnest for several days.
I'm not sure where you are, but if you're in a major city in the US, try to hook up with a local chapter of the American Pilgrims on the Camino at
http://www.americanpilgrims.org/local-chapters and find some Camino veterans who can advise you on trail conditions and the practicalities of the journey itself. If you're not in the US, there are similar organizations in many other countries, such as the Confraternity of St James in the UK or the Canadian Company of Pilgrims in Canada.