Change reporter level temporarily

[Iv4n]

Hi,

How do I change the app/models/ability.rb and gitlab-rails/app/policies/project_policy.rb
file? 

I need to complete a migration from Trac to Gitlab-9.4.2. I need the "reporter" level to not have access to the file browser(project) or repository sources through the web interface.

I still do not know the Gitlab body, nor do I have much knowledge with Ruby.

And I have some pressure to put on the air right away.

I saw something on this issue #12736, but it was not clear to me

Best regards.