Provide a method for the player to swap 5 random tiles from their hand

To do this we must firstly add a new command to the GetChoice Method for this.

private static string GetChoice() {
    string Choice;
    Console.WriteLine();
    Console.WriteLine("Either:");
    Console.WriteLine("     enter the word you would like to play OR");
    Console.WriteLine("     press 1 to display the letter values OR");
    Console.WriteLine("     press 4 to view the tile queue OR");
    Console.WriteLine("     press 7 to view your tiles again OR");
    Console.WriteLine("     press 5 to swap 5 random tiles from hand"); // <- New Command here 
    Console.WriteLine("     press 0 to fill hand and stop the game.");
    Console.Write("> ");
    Choice = Console.ReadLine();
    Console.WriteLine();
    Choice = Choice.ToUpper();
    return Choice;
}

Then we need to actually add the logic for the command in the HaveTurn method with a new else-if/choice for 5.

// Some stuff was here

else if (Choice == "5") { // Swap 5 random tiles command
    Random random = new Random(); // To select tiles to remove

    foreach (int X in Enumerable.Range(0, 5)) {
        String newTile = TileQueue.Remove(); // Get New Tile for hand
        TileQueue.Add(); // Replace taken tile with random new one
        int removalTileIndex = random.Next(0, PlayerName.Length-1);

        PlayerTiles = PlayerTiles.Remove(removalTileIndex, 1).Insert(removalTileIndex, newTile);
    }

    Console.WriteLine("New Hand: {0}", PlayerTiles);
}

// Some stuff was here

The only part of the above method which I feel may be somewhat confusing is the assignment of the PlayerTiles variable. "String".Remove() and "String".Insert() both return a new string with the desired logic of the method executed. Meaning u can chain these commands as I've done above instead of perhaps doing this:

String removed = PlayerTiles.Remove(removalTileIndex, 1);
String inserted = removed.Insert(removalTileIndex, newTile);
PlayerTiles = inserted;

You cannot, NO MATTER WHAT, just call the instance method PlayerTiles.Remove() or PlayerTiles.Insert() and expect PlayerTiles variable to have that value stored automatically. Both these methods return a new string instead of changing the existing string upon which they are run.

Aside from that, I feel this method is quite simple.