What are some ways to make tae kwon do an activity that disabled people can participate in?

I am looking for activities to do with a group of individuals that have disabilities. They have a variety of different abilities and are a variety of different ages. Feel free to include any physical activities that you have done and found successful! I was thinking of doing Tae Kwon Do but didn't know a good way to start. Anybody have any good sites to check out? Thanks!