The point of High Dynamic Range techniques is to help you creating a better image by combining multiple images that have variying amounts of exposure, but are otherwise the exact same image. There is automated software out there, but the concept doesn't require software, just an understanding of layers.
For more complex compositions, you will need to employ software to automate the process, click here for an example.
Here's a James method:
1) load two exposures bright/dark
2) select all on bottom layer
3) create layer mask on top layer
4) Go to channels, show layer mask
5) past image onto layer maks