Its not really that hard for even the newest person. Just a series of simple steps in a specific order. Its almost self intuitive and video can go further in such simple learning circumstances. Some can do it in under a half hour or even faster just with video help. Let him try, it is unlikely he will wreck anything and exchanges are possible. It will build his sense of accomplishment, confidence, and pride, at very little risk. Every time he looks at it, uses it, will be a joy beyond just having a cool PC, it will be his creation, alone.
Good luck
Your more than welcome, I love helping build PCs. Send me his parts list and a what he will be using the PC for. A budget ballpark would also help. Then I can give you some advice an recommend videos to help get the most for his budget and needs.
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