Flooring Tile - kitchen backsplash in extension area

I just closed a doorway in my kitchen (contractor did it) so I have a new area where I need to add backsplash. To make everything match, I'd like to take off all my old backsplash tiles and replace with new ones.

Questions:

1. Is this a very difficult job? What's the best way to remove tiles and replace with new?

2. What do I need to determine about the new area (the doorway that was closed) to ensure that it is ready for tiles to be added. I don't know what material was used, but I'm suspecting it was MDF. Maybe sheetrock? What questions should I ask my contractor, or what instructions should I give him about prepping the new area so it is ready for tiling?

the ease at which the tile comes off the wall depends on alot of variables ,what was used to attach the tile to the wall,who put it on etc.For the most part the age will define how it comes off,if the tile has been there for awhile then the mastic is probably crystalized and the tile will come off relatively easy,or if mud set then they will be a bear.The new surface will not need much prep maybe tape the seams and that will do it,you want to use a god mastic like tec double duty to adhere the tile to the wall will last along time good luck and let us know if we can answer anything else for ya!:cool: