My friend theres is many ways. The easiest of all just download it straight off the Internet. If that not what you are looking for you must be more descriptive.
Look at the back and message me back with what it looks like.
How many plugs are there, how many cords are plugged, and what ports are available to use.
For a DVR, there should be a USB port and most likely an ethernet port(Internet). From there message me back and we will work from there.