Generate List from another List with updated value in C#

output what i want :

{ "Test1", "Test2", "111" }

{ "Test1", "Test2", "222" }

{ "Test1", "Test2", "333" }

            List<string[]> myList = new List<string[]>();
            myList.Add(new string[] { "Test1", "Test2", "345" });
            int instances = 3; 
            List<string[]> assetId = new List<string[]>();
            id.Add(new string[] { "111", "222", "333" });

            var tmpRecords = (from e in Enumerable.Range(0, instances)
                              from x in myList
                              select x)
                              .ToList();

            tmpRecords (assetId);

            for (int Index = 0; Index < id[0].Length; Index++)
            {

                tmpRecords[Index][2] = assetId[0][Index];
               
            }

Help will be highly appriciated.