Hey LuckyDev,
if you want to clear a locked route in mechanical signalboxes you have to do following steps:
1. set the Signal back to "Stop"
2. press with Ctrl+LMB the black button under the white coloured "window"
3. the white coloured "window" should now red again.
4. set the Lock-Lever in "Neutral"
5. set all Point-Lever and Lock-Lever back in default position
and thats it youre done.
If you need more help with the "Dispatcher"-Mode from Train Driver 2 feel free too send me a
direct MessageSincerly
Saix95 [Trainer-in-training]