Even granting that the goal is good, how do you carry out the plan?
Literal
Purpose [topic-は] good [granting-としても], how that plan [obj-を] execute [Q-のか].
~としても ('even assuming/granting that') concedes a point before challenging the next step. 実行する ('execute, carry out') is Sino-Japanese. どのように ('how, in what way') is more formal than どうやって. The のか ending makes the question pressing.