using System;
using System.Collections.Generic;
using System.Linq;

static class Program
{
    public static List<T> Splice<T>(this List<T> source, int index, int count)
    {
        var items = source.GetRange(index, count);
        source.RemoveRange(index, count);
        return items;
    }

    public static void Main()
    {
        var data = new List<int> { 1, 2, 3, 4, 5, 6 };
        var spliced = data.Splice(2, 1);
        Console.WriteLine($@"Old enumerable: { string.Join(", ", data.Select(d => d.ToString()))}");
        Console.WriteLine($@"Spliced: { string.Join(", ", spliced.Select(d => d.ToString()))}");
    }
}