To open KWin from the terminal, you can use the following command:
```bash
kwin_x11 --replace &
```
This command will restart KWin, which is the window manager for KDE Plasma. The `--replace` option tells KWin to replace the current window manager. The `&` at the end runs the process in the background.
If you're using Wayland, you might need a different approach:
```bash
kwin_wayland --replace &
```
Make sure you save any work before running these commands, as replacing the window manager might cause your screen to flicker or temporarily disrupt your session.
