彼は現在の地位を獲得するのに一歩一歩戦いとらねばならなかったのです - lucifuge @Wiki

和文での述語は2つ。「地位を獲得する」と「一歩一歩戦いとる」。
主文は明らかに後者。こちらを先に書いておいて、副詞的に前者を修飾させるのが良さそうだ。

He had to go up step by step, and finally have achieved the present position.

うーん？

He has achieved the present position step by step.

あるいは、

He has gradually achieved the present position.

模範は、

He has had to fight every inch of his way to attain his present position.