OS X file permissions prevent me to delete files
That easy_install came with the system, it's not the one you tried to install.
The files coming with macOS are protected by system integrity protection.

On my machine this looks like:

$ ls -lO /usr/bin/easy*
-rwxr-xr-x  2 root  wheel  restricted,compressed 925 31 Jul 04:27 /usr/bin/easy_install
-rwxr-xr-x  1 root  wheel  restricted,compressed 454 31 Jul 04:27 /usr/bin/easy_install-2.6
-rwxr-xr-x  1 root  wheel  restricted,compressed 458 31 Jul 04:27 /usr/bin/easy_install-2.7


"restricted" means "protected by SIP"

If you want to use PIP on the mac, create a virtualenv in your home directory and do everything there, then you'll be independent from the system libraries.