Okay... you have a player under major league contract sitting in DFA who has cleared waivers, and you want him on a minor league team and off the 40-man...
1) If he's not there already, put the player on the 40-man
2) Move the player from DFA to the minor league roster
3) Drag the player from the 40-man to the white box
He only has to be on the 40-man while you're removing him from DFA, so in this scenario, the order of the steps matters.