Install El Capitan Without Internet

I have a few MacPro3,1's at my school I'd like to update to El Capitan 10.11.6. Currently they're running 10.5.8. I've got really slow WiFi-internet access, but the MacPro's do not have Airport. How do I attack this?
I want to make an up-to-date USB-install stick. I know I need to get hold of El Capitan, but my personal MacBook Pro is still running Mavericks. I can only update to Sierra. So I have to find an El Capitan-running Mac, but if I manage to get hold of the El Capitan-installer, it will be tied to their Apple-ID, right? Will El Capitan install without internet access?

Capitan
  1. Can you plug your Mac into ethernet access at work?
  2. not really sure what you mean by 'secure mode where you can install el capitan'. Sounds like your IT department may have things arranged so that Macs cannot connect. Perhaps your IT department can help you get wireless access.
  3. Take your mac somewhere else where there is internet access.
  4. Take your mac to your local Apple Store. They'll help you.
  5. If you have access to another Mac that does have internet access, perhaps a friend that has a mac, you can download the El Capitan installer and put it on an 8 GB flash drive (thumb drive) with diskmaker X http://diskmakerx.com/ . Then you can use the flash drive to boot your Mac and install El Capitan.
  6. why did you need to reinstall El Capitan?

Download El Capitan Installer

Dec 17, 2015 3:40 AM

Install El Capitan Without Internet Connection

If your computer already has OS X Yosemite installed, Unibeast will just update Yosemite to El Capitan normally, without deleting any of your apps or files. A separate hard drive: Mac OS X needs its own hard drive (a minimum of 10 GB of space is required, but at least 50 GB of space is recommended). Download: OS X El Capitan This downloads as a disk image named InstallMacOSX.dmg. On a Mac that is compatible with El Capitan, open the disk image and run the installer within, named InstallMacOSX.pkg. It installs an app named Install OS X El Capitan into your Applications folder.