However, do not open my MBA reassured me because I had never done.
And then change a hard drive laptop, it seemed complicated to me.
After much hesitation, I took the leap. And .....
...
...
the whole operation took less than 10 minutes !!! Unbelievable.
I followed exactly the explanation (summary) of the record and everything worked well.
It must be said that the Apple Disk Utility does wonders.
Only thing they say to press the "option" key during startup to access the Utility menu.
But with the lack of results of this method, I opted for "cmd + R" which worked very well.
I am delighted, my Macbook is worn like a charm! :)