expression
how can (one) do something; what should one do to...
Used to ask for a method or way to achieve something, often with a sense of uncertainty or seeking advice. Commonly followed by いい, よい, or a potential form.
どうしたら日本語が上手になりますか。
How can I become good at Japanese?
どうしたらいいかわからない。
I don't know what I should do.