Hello, i was wondering how i could watch my replays from my game, but without the LFS game running? Do i need a program for this?

You can't - you need to use LFS.

The LFS replays are not videos, but the data that comprises of the movements and actions of the vehicles and racers.

If anyone wanted to make a replay program, they'd basically have to make LFS all over again, or actually run LFS and embed the LFS window within it's own.

Edit: or, as AlienT says, you could record them from LFS, using fraps or something similar, and then play them using any old video program.

I suppose you could make a movie using the replays