You don't need that whole class; only the snippet loading the Texture is relevant. Here's a method:
public Texture2D LoadRawTexture(string filePath, GraphicsDevice graphicsDevice)
using (FileStream fileStream = new FileStream(filepath, FileMode.Open))
return Texture2D.FromStream(graphicsDevice, fileStream);
Important to note is you must dispose the Texture2D when you're done with it after loading it in this manner.