Recovering the APIC Password
Follow these steps to recover the APIC password.
Create and save an empty file named "aci-admin-passwd-reset.txt".
Add the file to a USB drive. You can format the USB drive to FAT or FAT32.
Connect the USB drive to one of the rear USB ports on the Cisco APIC.
Reboot the Cisco APIC using Cisco Integrated Management Controller (CIMC) or by hard power cycling the device.
Press the Esc key during the 10-second countdown timer that appears at the top left to bring up the list of boot targets.
Press the e key to edit the default grub line.
Go to the line that begins with "linux." Using the End key or Right Arrow key, move the cursor to the end of that line and append "aci-admin-passwd-reset".
Press Ctrl+X to boot the entry.
It may take a few minutes for the new password to take effect.