Remove unwanted instances from ServiceCollection in ASP.NET Core 3.1

At first glance this article sounds strange or has no sense. Well, this is wrong because it’s based on an unfortunate experience of recent times. I recently had the following experience: I was developing my Web API without too much pain until the moment when I discovered an unexpected behavior, I realized that one of my services did not have the desired behavior , and I discovered that its interface was registered with another instance than the one I coded for my Web API. This could have happened because I reused a legacy layer and I used an extension method which allows to automatically register instances by scanning the assemblies of my application. I am writing this article in order to show you how I managed to solve my problem other than simply renaming my interface, by simply deleting the registration of my service in the dependency injection container. This article will go a little further, I will show you how to unregister any type of service.