I need some help guys. I've built a very big tower from cobblestone and now i want to change cobblestone to obsidian (Black Tower Of DOOM ). Ithoght that MIneEdit can do this but it's not working for me so if you know tool that can make it i'll be very glad.
Install it and open up the world your tower is on, select the tower using the select tool, click fill/replace, and replace cobblestone with obsidian. Or, if you want to post the save I could do it for you.