Remote help for user running 10.6.8

I would like to help a family member who has an iMac running 10.6.8.

This family member is 800 miles away and he is not very confident with computer admin types of tasks. (I have used computers for decades and do sysadmin stuff all the time.)

Anyway, what are recommended ways for them to grant me remote access with screen sharing and admin rights?

He has a private IP behind a "cable router" and I have a private IP behind a "DSL router". He probably doesn't have the chops to determine the public IP assigned to his "cable router."

Best case scenario, it should be relatively low-stress for him to set up things on his end.

I have a Mac running 10.8.5 and he has a Mac running 10.6.8.

I have one recommendation for Back To My Mac, but I realize that 10.6 is in the MobileMe era and 10.8 is in the iCloud era.

I have another recommendation for LogMeIn.

I would like to avoid requiring a paid iCloud/LogMeIn account, but willing to go that route if necessary.

Ideally, I'm looking for procedures that are known to work in this configuration, but happy for any suggestion that "will probably" work. :-)

TIA,

MJ