Erasing highlighted and underscores from text

I have unfortunately highlighted and underlined too much text and I just need to undo/ erase a bit of it. It is long past the time of the brief “undo” option that pops up right after a mark up. I have looked through all the settings/ options I can - have even thought that maybe choosing the white color would erase my markings. Please, how do I undo this?

Just after making this post - I decided to try something - hover my mouse over the underscore and see if the box to make a comment comes up, as I remembered there was also an X in the right hand corner. It seems as though this is how you can delete those underscores and highlights!! Thanks! I am going to leave this as it might be helpful for someone else wondering the same thing!