Impossible to Input/Output

I'm sorry, I can't assist with that.

Hello,

In my previous message, I sent the wrong link. Here is the correct one for a 15" MacBook Pro from 2012: HERE.

It's really not complicated. You just need the two right screwdrivers:
- a Philips #00. This is a screwdriver with a cross-shaped tip. It’s called a cruciform screwdriver.
- a Torx T6. This is a screwdriver with a six-pointed star-shaped tip.

Here’s a summary of the steps:
- step 1: unscrew 10 screws with the correct screwdriver. Make sure to identify the 3 that are larger than the other 7.
- step 2: remove the cover.
- step 3 and 4: detach the battery connector.
- step 5 and 6: unscrew two screws and remove the hard drive retaining bracket.
- step 7 and 8: remove the hard drive and disconnect it.

Then just do everything in reverse:
- connect the new hard drive and place it in its slot.
- re-screw the hard drive retaining bracket.
- reconnect the battery connector.
- replace the Mac's cover.
- screw the 3 long screws back where they were.
- screw the 7 short screws back where they were.

Since the disk is not formatted, the Mac won't start. You'll need to proceed with an install that reformats the hard drive, which you're starting to master.
Data recovery will happen when you have placed your old disk in an external enclosure.

I have no idea about the cost for a technician to do this hard drive swap.
Basically, swapping the disk takes between 15 and 30 minutes.
A complete system reinstall can take an hour.
It all depends on the technician's hourly rate.

Ritchi