The full sentence: 息子はなんでもやりっぱなしで、困っています。彼が出ていった後の部屋を見ると、大変です。パジャマは脱ぎっぱなし、タンスは開けっ放し、テレビは付けっぱなしです。どうしたら、きちんとした子供になるでしょうか。
My attempt at translation: "I am concerned about my son because he leaves everything unfinished. When I look at his after-he-moved-out apartment, it is terrible. His pyjama is lying around, his chest of drawers is left open and his television is constantly left on.
how can he do something precisely did sure becomes a child"
Basically, I can't translate this last sentence at all.
I can still make some sense of
子供になるでしょうか
"he sure becomes a child"
But I can't in any way connect this to どうしたら let alone どうしたら、きちんとした to the rest of the sentence since I have no idea what to do with this した. According to jisho, きちんと is a suru verb, so I guess きちんとした should work like an attribute to こども, but taking this route my translation made no sense at all. If I assumed that
どうしたら、きちんとした
and
子供になるでしょうか
are two parataxes, then it could somehow work out:
"How can he do precisely (like) he did"
"He sure becomes a child, doesn't he?"
However, this requires quite a lot of assumptions and one extrapolation ("'like' he did") which aren't backed up by anything.