1. Transforming a strategy into action: This is the most common interpretation and implies that you are taking a strategic plan and putting it into practice.
2. Transforming a strategy through action: This interpretation suggests that you are changing a strategy by taking action.
To be more precise, you could rephrase the phrase to clarify its meaning:
* Implementing the strategy: This clarifies that you are putting the strategy into action.
* Activating the strategy: This emphasizes that you are making the strategy operational.
* Taking action to transform the strategy: This clarifies that you are changing the strategy through action.
The best phrasing depends on the specific context and what you want to convey.