Once you have the installer (usually found in your /Applications folder as "Install macOS High Sierra"), you need to move it to a USB drive (at least 16GB). Method: Using the Terminal (Recommended) Connect your USB drive and rename it to MyVolume .
: The system was specifically optimized for flash storage, significantly boosting responsiveness on older Macs upgraded with SSDs. macos high sierra 10136 dmg install
: Use the official macOS High Sierra download link which will redirect you to the Mac App Store. Once you have the installer (usually found in
macOS High Sierra - Technical Specifications - Apple Support macos high sierra 10136 dmg install