Payment by instalments is one of the terms of payment that has been accepted.
分期付款是通常被接受的一种付款方式。
It doesn't make much difference to me what you do.
你干什么对我没有多大关系。
It's quite simple. You put a very hot, wet cloth on your shoulder for one minute. Then put a packet of frozen peas on the shoulder for one minute. And so on and so on.