we don't actually know what psu he has, making ANY assumption is not a good idea. the only assumption it is safe to make is that "if it does not have the proper connections, then you need one that does has the proper connections"
we are not just trying to get him to buy a new psu for no reason. we've all been doing this a long time and have seen what can happen. feel free to take all the risks you wish in your own house, with your own system and your own money. but when suggesting others make dangerous choices, you are quickly going to be corrected.
what i would do is to educate yourself a bit more about how a psu works, think a bit about what an adapter actually does (simply changes the way a connection looks but DOES NOT MAGICALLY CREATE MORE POWER) and then ask some questions if you still don't understand what is happening.
we are more than happy to help educate if you're willing to learn