To promote by bot promotion, you need first to win your conference.
Then, from the group of teams who won their conference, but were not overall league champions, the teams with the best records (tiebroken by PD) are selected for promotion.
Bot promotions only take place for bot controlled teams that are not already going to demote via relegation. The only difference is teams from higher divisions that are bot; they demote all the way down to D5, thus opening potential spots in the division below where they are relegating.
Typically there are only a few bot promotions into D3, but this season I think there are a few D2 teams that have gone bot. That opens spots in D3 which you might be able to get into. I don't think I'd bank on it though.