1. Set a static ip address on your DVR (something like 192.168.1.10) the ip address may vary based on your router make and model.
To find out what ip address you can give it just connect your computer to your router and open up a command prompt by going Start>RUN and type in cmd (little black dos window will open up)
type in "ipconfig /all" without the quotes and hit enter
look for your ip address
if your ip address looks like this 192.168.0.100 than you can assign the camera something like 192.168.0.10 or something like that.
fill in the rest of the fields like subnet mask and default gateway to match yours on the black window.
2. You need to setup port forwarding on your router
http://kbserver.netgear.com/kb_web_files/n101145.asp
3. find out what your external ip address is by going to
http://whatismyipaddress.com/ or if you have DDNS or no-ip setup than you already know what you are doing.
4. go to friends computer at his house or something and in the browser type in the "http://your external ip address:"port" without the quotes (usually port is 80 but you can change that in the settings on the dvr)
5. if you have done everything correct it will connect and ask you for some information like hostname, hostport, username and password.
for hostname: your external IP address
for hostport: the port you designated
for username: whatever username you designated (admin i believe is default)
for password: whatever password you designated (default may be something like 11111)
it should work, if not you have some advanced issues.