Download 'El Capitan', 'Mavericks' or 'Yosemite' from external link The HDD of my MacBook Pro (2012) dies and I bought a new one. The problem is that I don't have another Mac to download the OS from Apple Store...

Someone know from where can I download the OS El Capitan, Mavericks or Yosemite to install it and then download 'El Capitan' and from Apple Store and make a clean installation?
If you've updated your MacBook Pro with the newest firmware update you may start to Internet Recovery Mode and reinstall the original OS X (probably Lion).


Install your new HDD
Detach any external drive (especially any external Time Machine backup drive).
Restart to Internet Recovery Mode by pressing alt cmd R at startup.
The prerequisites are the latest firmware update installed, either ethernet or WLAN (WPA/WPA2) and a router with DHCP activated.
On a 50 Mbps-line it takes about 4 min (presenting a small animated globe) to boot to a recovery netboot image which usually is loaded from an apple/akamai server.

I recommend ethernet because it's more reliable. If you are restricted to WIFI and the boot process fails, just restart your Mac until you succeed booting.
In the opening window choose Disk Utility.
Partition your drive: 1 (or more) partition, GUID partition table, Journaled HFS+.
Quit Disk Utility and open Restore OS X
Choose your new volume to install OS X there.
After successfully installing and configuring OS X, open App Store and install the latest OS X (El Capitan).