Are you planning to reinstall the tiles in other areas? Then, you have to get rid of the adhesives present at the back of the tiles. You can remove them and use for different projects. Scrapping the adhesives will damage the tiles. So, you have to use the products that are made to remove the adhesives.
You have to get the right adhesive softening product as there are different kinds. You have to know what type of adhesives you have used while installing the tiles. Citrus-based remover works only on the latex-based adhesives. If the tiles are older then you can use solvent-based product, as they have oil-based glue. For new Ceramic Bathroom tiles, you can go with latex-based product.
When you are using adhesive softeners, you have to wear the leather gloves and eye glasses for protection. They contain toxic chemicals so; carry out the work very carefully. Use a paint brush to spread the solution and allow them to work on the tiles for sometime. Then scrap them out and wash with fresh water. If the adhesives are present yet, then you can use them one more time. After removing completely, you can use these for other areas in the house.