Need ceiling light fixtures replaced

Hello, I have two ceiling light fixtures that I would like to replace with my old ones. I don't think I need any electrical wires replaced or anything. I'm just too scared to change the fixtures myself, as the wiring is knob and tube. The fixtures look relatively new, so someone replaced them before. I want to put in a flush mount 6 bulb chandelier in the bedroom and a 3 light chandelier in the kitchen. Also, on a separate note, I bought some slate tiles (12"x12") for my kitchen. There is existing tile (12"x12") on the floor, a rigid kind of synthetic material possibly PVC or Vinyl, similar to the tiles used in schools. Anyhow, I wondering what the best way to go about these projects would be. I work for the iTunes Store and don't make a lot of money to throw around, lol if you want. It's still beats McDonalds ;)