Requires a Dummy account or Bots
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 ctf_2fort; 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. Use any of the Below Commands as needed:
mp_teams_unbalance_limit 0; - Allows you to stack teams
mp_idledealmethod 0; - Used to prevent from being kick for being Idle
mp_idlemaxtime 0; - Used to prevent from being kick for being Idle
mp_maxrounds 142; - Some maps rotate, this keeps it on the same map
tf_bot_add red - Adds Bot to Red team
tf_bot_add blue - Adds Bot to Blue
tf_bot_melee_only 1; - Sets the Bots to only Melee
sv_cheats 1; sv_gravity 1; sv_cheats 0; - Sets Gravity to low
sv_cheats 1; sv_gravity 800; sv_cheats 0; - Sess Gravity back to Normal
sv_cheats 1; nav_generate; sv_cheats 0; - Allows Bots to move on some maps where they dont.
Choose Sniper on Red team. Put a Dummy account or some bots on Blue team. Kill them with headshots 25 times to unlock.
Easier way to do this is load bots on 2fort. The do not move but you will be able to use the command sv_cheats 1; noclip; sv_cheats 0; to ender their spawn. You will want to use the Melee only command above to stop them from shooting you.