unpacking .pk4 files

[thetrainmaster1361]

Hey guys,
I want to modify a locomotive in rt3. From what i've heard, i need to unpack a .pk4 file in order to access the files that need modifying. However, I can't seem to find a program that supports unzipping that file extension. Perhaps I am approaching this the wrong way. Anyone have any suggestions?
Thanks in advance, Sam

[Blackhawk]

You need to download the TM Rolling-Stock Developer Kit which has a java based method of packing/unpacking pk4 files.

Gumboots wrote some nice instructions on how to use it: viewtopic.php?f=67&t=3393&p=34584&hilit=pk4#p34583

Also I moved this post to the Letters to the Editor forum as it's more related to RT3 than PC's.

[thetrainmaster1361]

Thanks!