The easiest way is Airdroid. The speed transfer depends on your wifi network:
https://play.google.com/store/apps/details?id=com.sand.airdroid&hl=fr
don't you guys find airdroid too slow?
I ended up transferring the files to a flash disk, and connecting the flash disk to my phone to transfer it. (i used a cable, usb in and micro usb out)