How to cut a .obj file in half? I might seem stupid and my request may seem obvious (that's what I hope) : 

I found a .obj file of a wolf head i like a lot. The thing is, for what I'm trying to do, I would only need half its head. See the wolf there : 



I tried following this tutorial : https://www.youtube.com/watch?v=U3J-oYFdyqQ ; but didn't get the results I hoped : on one side, only the silhouette was kept, no more details (vertices?); and on the other that's all that was left. See there : 



If you're still with me now you probably guessed : I never used Blender before. Now as a perfect newbie I'm hoping there is a way to just cut trough that wolf like it's a cake. Is it the case ? Or am I gonna have to "try hard"? (How?)

Wishing anyone who read me all the best !

Stay safe.

Kendrick

EDIT : I managed to cut my wolf following Jachym's advices. So i do now have half my wolf : 



My problem is now that when i export it, i lose every detail ! I only get the shape : 



Are there any export settings i should consider ?
You can use the Bisect Tool for that.
It's pretty simple.


In Edit Mode, select the whole mesh through Select > All
Use the Bisect Tool and adjust the parameters to your needs
Enable X-Ray Mode and select the parts you want to delete


Note: If you don't need a sharp cut, step 3. should be enough :)



Use the Bisect Tool to cut the object in half



Then enable X-Ray mode and select the parts you want to delete