Use putty for windows, a terminal for OS X or linux, or this for iOS Serverauditor
ssh root@ipaddress <--------replace ipaddress with your aTV ip address for example mine is ssh email@example.com
default aTV password = alpine
Follow these easy terminal commands. I have installed this on multiple atv2's and so have others, set your dns to auto not manual. This automates nearly the entire aTV plexconnect installation for you. ssh into your aTV and enter these commands after your navigated to the folder where you placed them (nitoTV is the easiest way to install openssh for ssh access, also server auditor ). Copy and paste this one liner using your favorite ssh client:
apt-get -y install git; rm -R /Applications/atvjailbreak; cd /Applications; git clone git://github.com/wahlmanj/atvjailbreak.git; cd /Applications/atvjailbreak; ./installatv.bash
once complete the aTV will reboot and you will have a new plexconnect button. Just sign into myplex and you should be all set.
Optional log back in to your atv via ssh after your atv reboots and type this if you want more apps by spoofing your iOS version to a higher IOS after navigating to the spoof.deb location:
dpkg -i spoof.deb
Hopefuly the autoupdate plist works if not you can manually update by typing this into a terminal window after you ssh into your atv:
You must be successfully signed into myplex in your PMS. Also you must have your PMS port forwarded and pointed at your PlexConnect host for this to work right on your router if using it outside your LAN. If PlexConnect resides behind for example a synology box you must open these ports as well for it to work outside your lan tcp/udp.
If you only desire PlexConnect to work for your local content and don't use myplex you can ignore the paragraph above this. If you share your content you still would need to be successfully signed into myplex in your PMS with your ports properly forwarded to you PMS host on your router or gateway.
Note - Keep in mind this will prevent AirControl to work since it uses port 80 which is required by PlexConnect.