Potential ultimatum for grandson

Backstory: My grandson (now 21) had an unusual upbringing with no dad and a mom who wasn't very parental. He moved in with me about a year ago. He did not finish high school and doesn't want to get his GED. He worked for a food delivery service but would only go sporadically and eventually stopped altogether. He is intelligent but never leaves his room and spends all his time on the computer. He claims that he is learning online about computer programming and that he can eventually get a job that way without a GED or higher education. It seems like he doesn't know how things work in the real world (i.e. job/bills/basic life skills) and has no interest to learn. He has terribly poor hygiene and I have had to ask him to bathe on several occasions because the smell is so bad. I have offered to help him get into college and even set up an appointment for him to meet with an advisor. I feel like I am getting nowhere and I'm considering an ultimatum for him to either get a part time job, go to school, or move out. I'm worried that he would end up living in his car if I kicked him out, which is why I haven't done this yet. Any advice? via /r/Parenting http://ift.tt/2xwzBiT