Whelp right now I can tell you from the picture you may need to replace the main spring if it has been compressed for a long period of time
Does he have any gear or plays paintball? Really to me (comparing to other people I know) it sounds like he may not really be interested/able to spend money to repair it or get equipment. If he was really interested, he would hop on it! You could offer to just take it off his hands and he not need to worry about it.