Usually you find a *.mix or *.mixtape file and place it inside your WC3 installation directory (the folder where war3.exe resides).
If the server you play on doesn't use anticheats then you might try any of dozens of maphacks available for 1.26. But if the server or the map has anticheats then you would need to look for a maphack that bypasses those antichests.
WTB original zMap for 1.26a maphack from Zoid that was really undetected from 2004-2011 years if someone still have it.
Contact me on Telegram @MacTep88 or Skype Creedtrup . Paying good money for this maphack.