How to remove the "Content available" info?

I would like to remove the “Content is available only for registered users. plus login and register info”. I just want certain info hidden to non-logged in users.
I removed the lines of code within the php file and it worked but I don’t think that’s the proper way. The next update will probably undo that. What would be the proper way? Thanks… I do like this simple to use plugin!

https://www.ads-software.com/plugins/only-for-registered-users/