I have successfully created a tiled map of various textures. Right now, i had a Vector4 in my own custom Vertex declaration deciding what texture each of the tiles should be. This is working perfectly. I can have any of my four tiles on the map, and any combination of them.
However, i would like to start having the tiles change, yet i do not know how to change this Vector4 of the vertices. They have been added to a vertex buffer if that helps you answer the questions.