You can edit the 'characsMovementAllowance', 'characsStrength', 'characsAgility', and 'characsArmourValue' stats. You can now edit the individual players on your team. Next, go to 'bb_player_listing' and locate all the players with the same 'idTeam' value that was found previously. Scroll down to 'b_team_campaign_save' to find a single entry. Use a SQL database editor to edit the 'Campaign.db' file in the '\Documents\BloodBowl2\Campaign\' folder. You can edit the stats of your players in offline Campaign mode.
Note: This procedure involves editing a game file create a backup copy of the file before proceeding.