I'm sorry for not perfect english. In time I'll do a good quality translate. If you could not get anything please feel free to contact me in comments. I will answer you as soon as possible.
To remove the back cover you will need a special screwdriver to form a five-pointed star. Such a great deal on Aliexpress.
![Nizhnyaya cover MacBook Air Nizhnyaya cover MacBook Air](photo/macbook-air-bottom-cover.jpg.pagespeed.ce.oZe3u-0_mS.jpg)
Unscrew the small screws and the cover is easily removed, can see inside.
![The insides of MacBook Air The insides of MacBook Air](photo/inside-of-macbook-air.jpg.pagespeed.ce.FHQTNfeEgf.jpg)
Of the "computer" inside is not so much a large portion of six energoyacheek. That is why he is able to work relatively long time (hours 2-4).
Some photos a little more close-up:
![The insides of MacBook Air The insides of MacBook Air](photo/inside-of-macbook-air1.jpg.pagespeed.ce.H62lp70Eda.jpg)
![The insides of MacBook Air The insides of MacBook Air](photo/inside-of-macbook-air2.jpg.pagespeed.ce.kNtyDtWPkh.jpg)
![The insides of MacBook Air The insides of MacBook Air](photo/inside-of-macbook-air3.jpg.pagespeed.ce.gQpv8tqRAd.jpg)
![The insides of MacBook Air The insides of MacBook Air](photo/inside-of-macbook-air4.jpg.pagespeed.ce.EG4DfzOuT-.jpg)
![The insides of MacBook Air The insides of MacBook Air](photo/inside-of-macbook-air5.jpg.pagespeed.ce.laHo0PIBiF.jpg)
![The insides of MacBook Air The insides of MacBook Air](photo/inside-of-macbook-air6.jpg.pagespeed.ce.L8z3mdMqPu.jpg)
Solid State Drive (SSD) is pulled out basic-need to unscrew the one fixing screw and pull.
![SSD SSD](photo/macbook-air-ssd1.jpg.pagespeed.ce.RhIbb0xiPc.jpg)
![SSD SSD](photo/macbook-air-ssd2.jpg.pagespeed.ce.k9ViKCRN0G.jpg)
![SSD SSD](photo/macbook-air-ssd3.jpg.pagespeed.ce.iEvyc1gH-K.jpg)
remove the fan
To do this you need to remove the ribbon cable that goes over it, unscrew the three screws and disconnect the fan power cables and adapters (pictured below it departs from the left edge of the fan unit).
![Preparing to remove the fan Preparing to remove the fan](photo/preparing-to-remove-the-fan.jpg.pagespeed.ce.bJGYOcjNFA.jpg)
The fan:
![Fan MacBook Air Fan MacBook Air](photo/macbook-air-fan1.jpg.pagespeed.ce.4pPJXIUSaJ.jpg)
![Fan MacBook Air Fan MacBook Air](photo/macbook-air-fan2.jpg.pagespeed.ce.CM9JefHwQm.jpg)
![Fan MacBook Air Fan MacBook Air](photo/macbook-air-fan3.jpg.pagespeed.ce.BAi4EyJQmC.jpg)
![Fan MacBook Air Fan MacBook Air](photo/macbook-air-fan4.jpg.pagespeed.ce._1ckquBtNB.jpg)
Until all the fault in the fan removed, have not analyzed further.