Go to: https://m.facebook.com/pages/launchpoint/liked_pages
Paste the following script into console (F12 -> console):
var unlike_all = ()=> {
[].slice.call(document.querySelectorAll('[data-sigil="action-title"')).filter(x=>x.innerText.indexOf('Unlike') !=-1).map(x=>{x.click()});
window.scrollTo(0,document.body.scrollHeight);
window.setTimeout(unlike_all, 3 * 1000)
};
unlike_all();
you're done!
it's not going to work automated
open the activity log and load some liked pages
then paste this line
[].slice.call(document.querySelectorAll('[aria-label="Action options"')).map(x=>{x.click()})
then this
[].slice.call(document.querySelectorAll('[role="menuitem"')).filter(x=>x.innerText.indexOf('Unlike') !=-1).map(x=>{x.click()})
you have to refresh the page and do the steps again
it cost me like 15mins to unlike 15k pages