The process is known as removing “diacritics” – see Removing diacritics (accents) from strings which uses the following code:
public static String RemoveDiacritics(String s)
{
String normalizedString = s.Normalize(NormalizationForm.FormD);
StringBuilder stringBuilder = new StringBuilder();
for (int i = 0; i < normalizedString.Length; i++)
{
Char c = normalizedString[i];
if (CharUnicodeInfo.GetUnicodeCategory(c) != UnicodeCategory.NonSpacingMark)
stringBuilder.Append(c);
}
return stringBuilder.ToString();
}