Open the command console: ESC > Gear Icon > Under the keyboard tab select Advanced > Check off Enable Developer Console
Press the ` button to open the console and type:
map sd_doomsday_event; hostname "boost"; sv_lan 0; sv_cheats 0; (I had to input this twice to be detected on my LAN for some reason)
That will create your match. Choose the Red Team. Then type the following command:
mp_teams_unbalance_limit 0; mp_idledealmethod 0; mp_idlemaxtime 0;
This will allow you to stack the opposite team. Then you can add as many bots as you like using the command:
tf_bot_add blue;
For this Achievement you should be able to earn this without the bots but the Bots can distract the Horseman from going after you.
Collect the tickets and cap the strongman game. When you get the Soccer game, just bump the ball into the opposing net 3 times for the achievement