You must address ALL of the comments from both examiners.
If you disagree with an examiner’s comments then you must provide a professional, logical and respectful academic argument as to why you disagree. Use the current literature to confirm your argument.
If only one examiner identifies a problem the fact that the other does not, does not invalidate that Examiner. Respond to all issues separately.
If an examiner is commenting on a part of your thesis which has already been published, you will still be required to update your thesis. The fact that work was previously published is not an acceptable academic argument to ignore examiners’ recommendations.