The website is infected and the PHP files inside need to be modified. Does anyone have experience in this area? thank you all

Question

The website is infected and the PHP files inside need to be modified. Does anyone have experience in this area?

There are not many files, about 30. I don’t know how to use PHP. Please help me. I will be rewarded

Thank you all

Answer 1

How to change it?

Answer 2

Amount, amount, amount