It took me literally 10 minutes to insert an old DVB-T USB stick in one of my AppleTV's running OpenELEC, install the tvheadend service addon, scan and configure the channels through the tvheadend web interface (automatic) and install the tvheadend client addon on both devices and point it to this AppleTV.
In 10 minutes I could watch DVB-T channels (TV and radio) on both boxes, read EPG information and schedule recordings. No reboot, no command line fiddling, no prior knowledge needed. And with this information, maybe you can do it in 5 minutes :-)
BTW I never heard of tvheadend before, but it looks like a great piece of software.