User Instructions Dig a hole to required size for post, half fill the hole with water and place the post in the hole. The material is already pre-mixed. There is no need for mixing. It can simply be emptied straight from the bag into the hole. Add the Remix Post Mix Concrete uniformly around the post, until it is above the level of water. If any dry powder remains visible at this stage, add additional water until absorbed by the material. Adjust the post into position and support appropriately until material set occurs, which takes approximately 10 minutes.