Hi, to remove old tile isn't so hard but can be very time consuming. What you need to do is get one started, I usually use a screw driver to pick and pry it up. One thing I like to always try is to keep from breaking. It will take some time to get the knack right with the prober angle. I have a tone of tools to use for taken up tile but I always find my self using that old trusty screw driver.
So a old screw driver and a hammer works best. How ever after you get the tile up you have to deal with the old thin set. Old putty knifes work best for this, just make sure you while removing the old thin set you go on a angle to the grain of the sub
floor. Other wise you risk chopping up the wood. Either way it's not to hard but rather just time consuming. Just be careful, broken tile can be extremely sharp.
Regards... Dominick