How to remove specific item from existed minecraft world?

Well, I have kind'a funny issue. I have my modded minecraft server (about 120 mods installed) and some world on it I've played a lot. I decided to add new mod - OreSpawn. When I added it I faced a lot of id conflicts. The thing is that OreSpawn has fixed base block id and other block ids are generated depending on this base block id value. So I had to dump all available block ids using NEI, then I selected the widest id range to fit all ~400 blocks from OreSpawn, changed base block id value so I had only two id conflicts in result. Those two conflicted items are from AppliedEnergistics. One of them is null item, I'm not quite sure what it is. The second one is tiny tnt. So i decided change tiny tnt id in AppliedEnergistics.config file. As you can guess this will change all existed tiny tnts in my world to something from OreSpawn. The funniest thing is that this "something" is block called "random dungeon spawner" and it generates gigantic dungeons/castles with tons of really nasty and hardcore mobs in places where my AE system, chests and basically all home was. I tried to downgrade my mod pack, find all those tiny tnt blocks in game and void them, but still I face this issue. Apparently, there are some chests in dungeons near my home with this item inside. So my question is - how can i find all those items with specific id in the world?... and remove them?

MCEdit can to this, according to this forum post. You can replace all blocks of a specific ID with another (e.g. Air).

Press Ctrl-A, and select your entire map. Then press 4, then R. Then put in IDs.

It's really easy, all you need to do is install this mod called "idfix" which will automaticly re-write all the IDs for each block so there are no conflicts.. if you install a new mod, also reinstall idfix! It's easy, I used it for my mod pack!