puts this under app/config/initializers/refile_rotate.rb

refile_rotate.rb

Refile::MiniMagick.prepend Module.new {
  define_method('rotate') do |img, angle=0|
    img.combine_options do |cmd|
      yield cmd if block_given?
      cmd.rotate angle
    end
  end
  
  define_method('fill_rotate') do |img, width, height, angle=0, gravity="Center"|
    # We use `convert` to work around GraphicsMagick's absence of "gravity"
    ::MiniMagick::Tool::Convert.new do |cmd|
      yield cmd if block_given?
      cmd.rotate angle
      cmd.resize "#{width}x#{height}^"
      cmd.gravity gravity
      cmd.extent "#{width}x#{height}"
      cmd.merge! [img.path, img.path]
    end
  end
}