Attaching trailers to a tractor or a tug is fairly easy: just back into the tow pin with your tractor, and it'll latch. The only way to un-latch it is to make a maneuver that forces the connection to be severed, there is no other way of detaching trailers.
OK, got that.
Now, I was pretty sure that with help like CLEO, someone must've made a mod like that. I've searched the web far and wide, but (aside from that fact, that searching for anything with the word "trailer" brings up movie trailers) I found many interesting and vastly more complicated things, than simply a function to detach the trailer of a semi.
Now, there's things like mods that let you detach and reattach train cars. I was under the impression that the trailers of semis should work similarly.
I also found an old forum post advertising something very similar to what I'd need, but unfortunately, all the links mentioned there are dead.
I also found a mod, that reaches deep into the game data and changes quite a bit of it. It also does way more that I'd ask for.
The reason why I can't use it is because it seems to break the game. No idea if it's due to a newer CLEO version, maybe it doesn't like the Steam version of the game. In any event, the game crashes while starting when this plugin is installed (I manually made a backup of the files this is overwriting, beforehand).
At this point, I believe I'm simply looking in the wrong direction. Even though this function hasn't been included in the original game, given that people have been releasing far more complex CLEO mods and scripts for GTA:SA since the game has been released - and are still releasing it, thanks to SA-MP, a comparatively simple function add-on seems almost trivial.
At this point, I'm asking for suggestions on what mod or plugin to use, or if I'm doing something conceptually wrong to begin with.