I understand you're looking for a guide on for Mac. However, I must inform you that there is no legitimate "free download" for this paid plugin. Silencer is a commercial product priced around $99–$129, and any site offering a free crack, keygen, or patched version is distributing malware.
Black Salt Audio offers a to all Mac users. This is a legitimate "free download" that requires no credit card, just an email address. Black Salt Audio Silencer for Mac Free Download
Since macOS is strict, you may need to allow the installer in System Settings > Privacy & Security . I understand you're looking for a guide on for Mac