Previous owners of our 1980's PDB (poorly designed bungalow)
installed ceramic tile in the hallway and livingroom- they didnt do a very good job of it.

We want to replace this flooring with hardwood.

I have lifted about half of the tile in the hallway to discover the tile was laid directly on the raw plywood floor sheathing. There is no subfloor.

So now we need to install a sub floor to bring the new floor level with adjoining rooms.

What is the easiest way to get the thinset off the sheathing?
Any suggestions would be welcome!I saw one post suggesting use of a rotohammer with a chisel what is this, and where can I get one?

thanks so much