A good children’s Mandarin-Mandarin dictionary should have a little space near the character that shows the “stroke order”, that is, the exact order in which you should write each stroke that makes up the character. Usually the stroke being written in that step is shown in red, the ones already written in black or grey. Just find the characters of his name. You might want to make him some worksheets of your own showing him the step-by-step process more clearly.
The general mantra is:
“Top to bottom, left to right, inside, outside, close.”
Of course there are exceptions to that, too, but generally speaking it works, assuming you can tell when something that looks like two separate strokes to a Westerner is actually one stroke and which direction it’s written in in the first place! So getting a dictionary with the stroke order information in it is probably your best bet. Either that or just tell a Chinese friend you need to have the stroke order and have them write the characters one stroke at a time, with a separate “picture” for each step (that is, the first one shows just the first stroke, the next box shows 2 strokes, and so on on up to the completed character).