Un-merging merged track and truck pods: the big problem is knowing which files were/are shared.
A first step would be to use <a href=http://mtm2.com/~mtmg/downloads/mtm2/mdmre/Winpod.zip>Winpod</a> to extract the pod to a new folder and create a response/LST file. You could then edit the LST to include only the files you want, load the LST back into Winpod and create a new pod, you would have to make multiple edits of the list for each merged pod you wanted to re-create. In some cases, not knowing what files were shared would make it difficult to create a working pod.
A good thing about the LST file extracted from merged pods is that the pod filenames are usually in order - if a truck was merged with a track then all the truck files are likely to listed together.
Note: Winpod will allow you to right click on TRK and BIN files within a POD and 'examine' them. Examining those files will show you all the files used by a truck (experience with TRK files would help), using this info can help you re-create a single truck pod.
I have removed unwanted stuff (trucks and rumbles) from merged track pods in the past. The easiest option is probably to remove a truck or trucks from a track pod. All you have to do is edit the LST file, remove the truck files and re-create the pod. I have done this several times myself because I don't like trucks that are packed with tracks, there is also the fact that some MTM1 trucks packed with MTM1 tracks can cause errors in MTM2.
Some people have released tracks that consist of different layouts or race types using the same basic textured terrain -- different tracks all sharing the same textures. I have gone in and deleted all the variations I didn't want (by editing the LST file) and re-creating the pod with the tracks I liked. It's easy to spot the unique track data files and remove them thanks to them all having the same basename, while leaving all textures in place.
Warning: Traxx can handle long filenames (names longer than eight characters), Winpod cannot. If someone used long filenames in their track it will make re-podding with Winpod impossible unless the .SIT is edited to reflect the names shortened by Winpod (which would likely end with "~1" or "~2".
Note: merged, edited or podzipped tracks cannot be used in multiplayer racing unless all participants have the identical edited POD.
I wrote all that as a reply a long time ago, having just found it again on my drive I thought I'd post it here. I suspect this info is more than enough for experienced editors and that it's not enough for people who are not. To simplify things: the easiest (though inefficient) way of removing a truck would be to remove only the .TRK lines from the .LST file, and the .SIT lines to remove a track, before rebuilding the .POD. Inefficent: doing it this way would remove the trucks and tracks from the game while leaving all of the extra files in the POD.
