hi, we are putting in a ceramic tile floor and pulling out this old vinyl subfloor. i put an arrow on the photo in question. we want to remove the top tiles. but i am curious if the subfloor is the floor underneath it and that gets removed and replaced as well? then i see there is a layer of something grey, and another layer of wood. can you please just let me know which layers are what and what can be removed and what needs to stay? because the floor currently is level with the hardwood floors in the rest of the house, so if that layer underneath the tiles can be removed and replaced with a new subfloor, that would likely be best for a flush and even finish. thanks!!!!