Friend with large student loans

I am trying to help my friend. He had taken out some student loans but failed to secure a stable job upon graduation. He was, thus, unable to pay off the loans. After adding the late fees… the loans have now grown to huge amounts. He ignored the letter which he received from the collection agency. Paying back all the 100k+ is out of the question. With the current level of income, he can barely pay 10% of that in the next several months. Unfortunately I do not have any experience with this kind of issue, so I don't know what the next step should be. The amount of debt is so large it makes me dizzy. If he negotiates with the collection agency, I'm not sure what amount we can reasonably offer. My friend hopes to eventually secure a mortgage in the next several years. He understands this is a long-term issue that may take years to resolve, and hopefully he will stick to whatever strategy I can come up with for him. But right now I need guidance. Any advice would be appreciated.