And Moses and Aaron did so, as the LORD commanded; and he lifted up the rod, and smote the waters that were in the river, in the sight of Pharaoh, and in the sight of his servants; and all the waters that were in the river were turned to blood.

Moses and Aaron followed God's instructions. They used a stick to change the river water into blood, right in front of Pharaoh and his helpers.

King James Version

Simple English

* Work in progress - there may be occasional inaccuracies