I notice you haven't gotten much help with this, so thought I would put my 2 cents in, even though I'm not an experienced teacher!
I would try to emphasize the listening/speaking part of your class more than the other parts. Lots of repetition of useful phrases and substitution of other words in the phrases so the students get something useful right away.
Perhaps you could get or make some easy worksheets so the students who are particularly struggling can work on their own project while the rest of the class writes or reads something else. I've seen some worksheets where the words are accompanied by pictures so the meaning of the words is clear, and maybe the letters of each word can be traced first and then written for practice. There are many resources for non-reading children (pre-k and kindergarten worksheets) that you might be able to use or adapt, though of course they will probably be very child-oriented with teddy bears, etc.
Many communities now have literacy programs for adults. Maybe your local public library or a local county program would have some materials for you.
Sounds very challenging!