My wife did want to save some screenshots of our posts on facebook, but she wanted to remove all *like* and *reply* buttons. Besides, she wanted to change the relative date and time to an absotule one.

normalize-dates-and-remove-reply-and-like-link-on-facebook.js

/**
 * 
 * @param {HTMLSpanElement} timestampContent 
 */
function getAbsoluteTime(timestampContent, timestampContainer) {
  const ABSOLUTE_TIME_ATTR = 'data-tooltip-content';
  const attr = (timestampContainer && function (att) { return timestampContainer.getAttribute(att); }) || function () { return timestampContent.innerText };

  let absoluteTime = attr(ABSOLUTE_TIME_ATTR) || attr('title');
  absoluteTime = absoluteTime.indexOf(",") !== -1
    ? absoluteTime.substr(absoluteTime.indexOf(",") + 2)
    : absoluteTime;

  const matcher = /([0-9]{1,2})\/([0-9]{1,2})\/([0-9]{4})\s([0-9]{2})\:([0-9]{2})/gi.exec(
    absoluteTime
  );

  if (matcher && matcher.length === 6) {
    const day = matcher[1];
    const monthIndex = parseInt(matcher[2]) - 1;
    const year = matcher[3];
    const hour = matcher[4];
    const minutes = matcher[5];
    absoluteTime`${day} de ${
      months[monthIndex]
      } de ${year} às ${hour}:${minutes}`;
  }

  return absoluteTime;
}

function updateTimeToAbsolute() {
  var abbrsWithTimestamp = document.querySelectorAll('abbr.livetimestamp');
  abbrsWithTimestamp.forEach(abbr => {
    abbr.classList.remove('livetimestamp');
    const span = abbr.querySelector('span') || abbr;
    const absoluteTime = getAbsoluteTime(span, abbr);
    console.log(`from "${span.innerText}" to "${absoluteTime}"`);
    span.innerHTML = absoluteTime;
  });
}

function removeCommentInputs() {
  const textboxes = document.querySelectorAll('div[contenteditable=true]');

  if (textboxes != null) {
    textboxes.forEach(textbox => {
      let counter = 0;
      let toBeRemoved = textbox;
      while (++counter < 11 && toBeRemoved !== null) {
        toBeRemoved = toBeRemoved.parentNode;
      }

      if (toBeRemoved !== null) {
        toBeRemoved.parentNode.removeChild(toBeRemoved);
      }
    })
  }
}

function removeReactionAndRespondLinks() {
  const buttons = document.querySelectorAll('ul > li > div[role=button]')
  const ulTags = new Set();

  if (buttons !== null) {
    buttons.forEach(button => {
      if (button.innerText.toLowerCase() === 'responder') {
        const liRespond = button.parentNode;
        ulTags.add(liRespond.parentNode);

        liRespond.parentNode.removeChild(liRespond);
      }
    });
  }

  ulTags.forEach(ul => {
    ul.childNodes.forEach(li => {
      if (li.querySelector('.timestampContent') === null) {
        li.parentNode.removeChild(li);
      } else {
        const separators = li.querySelectorAll('span[aria-hidden=true]');


        if (separators !== null) {
          separators.forEach(separator => {
            separator.parentNode.removeChild(separator);
          });
        }
      }
    });
  });
}

function removePostActionButtons() {
  document.querySelectorAll('div > div > span > div[role=button]').forEach(a => {
    if (a.innerText.toLowerCase() === 'comentar') {
      const postActions = a.parentNode && a.parentNode.parentNode;
      if (postActions !== null) {
        postActions.parentNode.removeChild(postActions);
      }
    }
  })
}

updateTimeToAbsolute();
removeCommentInputs();
removeReactionAndRespondLinks();
removePostActionButtons();