Well its a bit difficult to explain to your 8 year old kid but i did this..

My daughter. how do they pick a new pope Daddy?

Me . well its like a Divine I spy with my little eye game sweetheart

My daughter. What do you mean Daddy?

Me. Well God picks some Bishop/cardinal or Priest and they have to guess which one God is thinking of.

My daughter. What if they guess wrong Daddy?

Me . Go to bed and stop asking questions!