I have a elderly lady with limited money who has a major issue. She has exposed wires throughout her garage and ask me to repair it. It has the old fabric wiring connected directly to the 6 gauge wires with no ground. From there goes up to a 4 inch junction box and then spider webs out to all the lights outlets end garage door opener. I would like to rip all that out and start over. My plan is to run conduit throughout the garage then wire it all in to a 2 breaker sub panel. My question is is there a way I can split the 6 gauge wire to two smaller gauge wires to feed the subpanel and can I put in a ground rod grounded and code. I need to split it because each breaker has its own leg any suggestions? note replacing the underground wire is not an option for her.