Remove Wiring for 2nd generation

I am trying remove Wiring for my device and the wire doesn’t come out at all. I feel like I am breaking something.
I don’t know what to do and my spinkler system is not working now. I tried pressing hard but not use.
Can some one show a picture or a video to remove? I don’t know if I am doing something wrong.

Try this: Can’t remove a stuck wire