Wordpress Theme Function Customization

I have a esports tournament based website. I host tournament on the site and users join it. Once the match gets done, i do submit scores of the users who joined it. Once the score is submitted, tournament brackets (knockout, ladder, round robin, league) types gets generated by the theme function on the tournament page and the tournaments get a mark as end. you can see on this page :: https://www.tournamentloot.com/tournament/test-2/

I want to customize this function. I don't want to submit users scores to get the tournament marked as end. I want to remove the brackets generate function from the theme and create a function in wordpress admin area to END the tournament manually. I also need a function to upload a image on the place where tournament brackets gets generated. Screenshots attached.

Note: I talked to my theme developers about this and they told me the files patch which may need to be custom coded for this task :: https://i.imgur.com/ZFmfTQa.png