Malware Removal from Website

My current website has been suspended due to malware being detected. I have the scan results and all the files or code that have been flagged. I need someone to access the site through the FTP portal, identify the issue, and fix it by either removing or amending the affected files. The goal is to keep only what is necessary so I can have my site reactivated. Please share your experience with similar website security issues and how you would approach this task.