YOU SAID:

if I told him that this has to be done that way, he would have done it my way

INTO JAPANESE

もし私が彼にこれはそのようにしなければならないと言ったら、彼は私のやり方でやっただろう

BACK INTO ENGLISH

If I told him it had to be done that way, he would have done it my way.

INTO JAPANESE

もし私が彼にそうしなければならないと言ったら、彼は私のやり方でそれをしたでしょう。

BACK INTO ENGLISH

If I told him he had to, he would have done it my way.

INTO JAPANESE

もし私が彼にそうしなければならないと言ったら、彼は私のやり方でそれをしたでしょう。

BACK INTO ENGLISH

If I told him he had to, he would have done it my way.