Below is the code snippet to call a method using reflection.
// Name of the .dll file
Assembly asm = Assembly.Load("DNFBusinessLayer");
// Name of the class where the method resides
Type tsm = asm.GetType("DNFBusinessLayer.MyManager");
// "Load" is the method name, if this method expect some parameter pass them as the last parameter as the array of objects
Object obj = tsm.InvokeMember("Load", BindingFlags.InvokeMethod, null, tsm, new object);
// Now suppose you have to bind the returned data in GridView, specify as DataSource (here I am assuming that it Load method will return collections
GridView1.DataSource = obj;
Hope this will help.