Changing Vertex data for a Mesh?

Hi There
Just starting out on my Unreal journey so please excuse the noob questions. I want to do a simple stretch effect on a mesh, I have the code to do it from my own C++ based engine I developed a long time ago but I am struggling to find info on how I can integrate this into Unreal, I have done it in Unity and it was very easy but it seems a bit harder in Unreal. I have a Blueprint method that I can plugin that gets the vertex data from an actor by using the Get Section from Static Mesh component. That seems to work and I can read through the vertex positions, change them and output a new vertex array. But how do I then apply that changed vertex data back to the mesh and have it change? Is there a component to do that? Or an example of some code to show how it could be done? Below is the simple blueprint I have at the moment.