The following 7 free liveries are easily installable via ACE (Start>Captain Sim>764 ACE MSFS2020>Online)

ACE is not included in the MSFS Marketplace version.

Boeing 767-400ER Delta Air Lines N828MH #1: Boeing 767-400ER Delta Air Lines N828MH
Livery name: Delta Air Lines N828MH
Aircraft type: 767-400ER CF6
Size: 37.02 MB

Boeing 767-400ER United Air Lines N76064 #2: Boeing 767-400ER United Air Lines N76064
Livery name: United Air Lines N76064
Aircraft type: 767-400ER CF6
Size: 21.01 MB

Boeing 767-400ER United Denver Broncos N76064 #3: Boeing 767-400ER United Denver Broncos N76064
Livery name: United Denver Broncos N76064
Aircraft type: 767-400ER CF6
Size: 21.09 MB

Boeing 767-400ER Continental N76064 #4: Boeing 767-400ER Continental N76064
Livery name: Continental N76064
Aircraft type: 767-400ER CF6
Size: 21.03 MB

Boeing 767-400ER Delta Skyteam N844MH #5: Boeing 767-400ER Delta Skyteam N844MH
Livery name: Delta Skyteam N844MH
Aircraft type: 767-400ER CF6
Size: 31.46 MB

Boeing 767-400ER Captain Sim House 2021 #6: Boeing 767-400ER Captain Sim House 2021
Livery name: Captain Sim House 2021
Aircraft type: 767-400ER CF6
Size: 31.94 MB

Boeing 767-400ER United Star Alliance N76055 #7: Boeing 767-400ER United Star Alliance N76055
Livery name: United Star Alliance N76055
Aircraft type: 767-400ER CF6
Size: 19.94 MB