Mindspring or earthlink (they are the same), will ask to speak to the person who's name the phone number's account is under ... this case your dad. They will ask him to verify his name, phone number and street address of the residence the dsl service is going to be installed. What happened with me was that my dad wasn't home but my cousin was so, my cousin just told mindspring that he was my dad and that was it. Not that i was trying to sneak it past my folks or anything, just a matter of fact that my dad wasn't home. The tech came over and all he did was give me the phone filters (i installed them myself). The tech was going to install the software but since i have a router i told him i didn't need it and just left the cd with me. He was in and out in 10 minutes, long enough to verify that the dsl line was connected at the phone company's end. I have the bill automatically charged to my CC so i only see it on my statement. Hope this helps but i would be honest with your dad first, parents can surprise you sometimes.
And good luck too, cause mindspring dsl rocks!!!!!