How to delete an object by id with entity framework

In Entity Framework 6 the delete action is Remove. Here is an example

Customer customer = new Customer () { Id = id };
context.Customers.Attach(customer);
context.Customers.Remove(customer);
context.SaveChanges();

The same as @Nix with a small change to be strongly typed:

If you don't want to query for it just create an entity, and then delete it.

Customer customer = new Customer () { Id = id };
context.Customers.Attach(customer);
context.Customers.DeleteObject(customer);
context.SaveChanges();

Similar question here.

With Entity Framework there is EntityFramework-Plus (extensions library).
Available on NuGet. Then you can write something like:

// DELETE all users which has been inactive for 2 years
ctx.Users.Where(x => x.LastLoginDate < DateTime.Now.AddYears(-2))
     .Delete();

It is also useful for bulk deletes.