If there is data on the drive you need to keep, make sure to save it on another hard drive.  You can transfer files to your computer's internal hard drive, use a USB flash drive, or upload to a cloud storage service such as Google Drive, DropBox, OneDrive, or iCloud. Most external hard drives can be connected to your computer using a USB or firewire cable. In some cases, an external hard drive may need to be plugged in using an AC adapter. It's in the upper-right corner of the menu bar at the top of the screen.  This displays a search bar. This opens the Disk Utility app. Alternatively, you can find the Disk Utility app in the Utilities folder, which is inside the Applications folder in Finder. All external hard drives are listed below "External" in the sidebar to the left in Disk Utility. It's in the button in the middle at the top of the Disk Utility app window. This is the name the hard drive will be renamed to once it is formatted. Use the drop-down menu next to "Format" to select a file system:   APFS:.  This is the newest Apple file system optimized for Solid State Drives (SSDs) and Flash Drives.  Select this option only if you have an SSD or flash drive and plan to only use the drive on Mac OS High Sierra or newer.  Mac OS Extended:  This has been the standard Apple file system since 1998.  Select this option if you have a mechanical or hybrid hard drive, if you are using an older version of Mac OS, and only plan on using your external hard drive on Mac computers.  exFAT: Select this option if you need your hard drive to be compatible with multiple devices, including Windows computers. It's in the lower-right corner of the Format window in Disk Utility.  This begins formatting your external hard drive.  It may take a while depending on your Mac's hardware and the size of your hard drive. When you are finished with your external hard drive.  Click the eject button next to your hard drive name in the sidebar to the left in Disk Utility.  Do not remove your flash drive until it is completely ejected.
احفظ نسخة احتياطية من البيانات المهمة. وصّل القرص الصلب الخارجي بجهاز الكمبيوتر. انقر على أيقونة العدسة المكبرة. ابحث عن أداة الأقراص عن طريق كتابة Disk Utility.app في شريط البحث ثم الضغط على زر الإدخال ↵ Enter. حدد القرص الصلب الخارجي. انقر على زر المسح Erase. اختر اسمًا للقرص الصلب الخارجي. حدد نظام ملفات. انقر على زر المسح Erase. انقر على زر الفصل المجاور للقرص الصلب الخارجي.