How to I exactly do the first few steps
"
You’ll need to check the filesystem first:
fsck -fy
Next, you must mount the root drive as writeable so that changes will save:
mount -uw /
CAN ANYONE PLEASE CLARIFY, STEP BY STEP, WHAT/HOW I DO THIS?
Depending on why you believe your Mac needs this done, and which model year
(and hardware + macOS or OS X) the reasons may vary and you may not need to.
Single-user mode, command-line & other beneath-the-GUI access points may not
be necessary. ~ Especially if an older Mac may really have a defective hard drive.
• Resolve startup issues and perform disk maintenance with Disk Utility and fsck - Apple Support
• Handling "overlapped extent allocation" errors reported by Disk Utility or fsck:
https://support.apple.com/kb/TA22517?locale=en_US
https://duckduckgo.com/?q=fsck+mount+-uw+%2F+mac+os+x&t=ffab&ia=web
And depending on the vintage and/or what system tools (installer DVD disk utility, etc)
you have available locally, you could replace an ailing hard drive. ~ There may be other
considerations based on what you actually have there. And most every year brought up
newer changes in various models of Mac configuration. Also: Please identify your Mac.
{Are you trying to use fsck as a troubleshooting tool? + What are symptoms of the issue?}
