V+ 기만 하면 돼요.

It is used to show that one can just do the behavior and is fine enough with no additional behavior.’-기만 하면 돼요’ is attached to the stem of the action verb. When you do so, the ‘N하다’ verb(전화하다, 숙제하다, 연락하다, and so on) should be used as ‘N만 하면 돼요’.

식사는 다 차려 놨으니까 이제 먹기만 하면 돼요.
We’ve got all the meals set, so all we have to do is eat.

편지는 썼으니까 보내기만 하면 돼요. 주소 좀 알려주세요.
I wrote the letter, so I just have to send it. Let me know the address.

내일 여행 갈 준비는 다 했어요. 이제 가방 정리만 하면 돼요.
I’m all set for tomorrow’s trip. All I have to do is clean up my bags.

Conversation:

아저씨, 집에서 쉽게 키울 수 있는 채소 모종 있어요?
Sir, do you have any vegetable seedlings that one can easily grow at home?

처음 키우는 거면 상추 모종이 좋아요. 요즘 많이들 키워요.
If it’s your first time, lettuce seedlings would be good to grow. People grow it a lot these days.

텃밭이 없어서 그냥 베란다에서 키울 건데 어떤 화분이 좋아요?
I’m just going to grow it on the veranda because I don’t have a garden, what kind of flowerpot would be good?

이 화분 정도면 모종을 여섯 개 정도 심을 수 있어요.
With this pot, you can plant about six seedlings.

처음 키워 보는 건데 어렵지는 않겠지요?
It’s my first time growing one but it’s not going to be hard, is it?

이삼일에 한번 물을 주고 햇볕을 잘 쬐어 주기만 하면 돼요.
All you have to do is water it once every two or three days and warm it well under the sunlight.

물은 얼마나 줘야 해요?
How much water do I have to water it?

한 번 물을 줄 때 흙이 흠뻑 젖을 정도로 주세요.
When you water it, give enough water so that the soil can get soaked a lot.

Related words
모종 seedling
상추 lettuce
텃밭 garden
쬐다 to warm
흠뻑 soak deep

Source: Yonsei University. Korean Language Institute