I really hope that he knows the consequences of getting a liver transplant and the all the risks of taking those drugs. So many doctors today schedule surgery without even telling the patient exactly what their doing to you. Their are tons of risks involved with taking immune-supressent drugs.
I don't know if you've heard of this but there was a story not too long ago about a woman who got the first face transplant in the world in France. There was a lot of controversy about her getting it done because of the horrible effects of the drugs. Yes she got a new face(which by the way was eaten by her dog after trying to kill herself, sorry to be so graphic)but is her quality of life without a face worse than what her quality of life will be taking these drugs. Many people said no.
Anyways, sorry about that, you can just ignore that. I hope he's open to this too. It can be so hard to calm yourself down and consider other options for disease treatment, especially when what you have is lifethreatening. I've been through it myself. This is probably why so many people don't look at other options to cure cancer. Their doctors scare them into chemo and radiation. Here I go again blabbing! So sorry.
You could try doing some research for him about ways to improve the liver and give it to him. You could print out some articles about the raw diet. Has he tried liver flushing? Maybe you could give him Andreas Morits's The Amazing Liver Cleanse. How about oil pulling? That's supposed to be helpful for the liver. Encourage him to explore all options. Just make sure that he doesn't do any heavy detoxing with such a weak liver. Everything he does should be devoted to strengthening the liver. Not detoxifying. Something Gerson points out in the article.