I'm new also but have used TSSplitter GOOGLE it(FREE)which will also join which is what you want..GOOD LUCK!!

I claim to no nothing but could use help here,I have 14 MKV264 Movies that after put through tsmuxer and onto fat32 External then played through PS3 are great!!
HOWEVER others will have no sound such as Transformers,Fantastic Four and Ice Age some will not go through the TSmuxer at all...
Any help would be greatly appreciated I am not a PC Wiz or anything so Idiot terms Please..LOL