So lets say i have this code
var builder = new ContainerBuilder();
builder.RegisterInstance(new MyType());
var container = builder.Build();
Then some time later I want to change the instance of MyType for all future resolves that are called on container.
You can also make use of the Autofac Lifetime event "OnActivating" and have your own controller object in memory which replaces the resolved instance like so
builder.Register<TInterface>(c => c.Resolve<TConcrete>())
.OnActivating(e => e.ReplaceInstance(new TInterfaceSubclass()));
https://autofaccn.readthedocs.io/en/latest/lifetime/events.html#onactivating