Get entity variables

Ok, I'm trying to understand ECS, by converting a classic GameObject with its monobehaviour components (MB_Test being one of them).
I have successfully used ConvertGameObjectHierarchy and Instantiated the entity.
Now I'm wondering how to access variables and functions from the Entity.
Let's say I have a Monobehaviour :

Code (CSharp):

1. public class MB_Test {
2. ...
3. float m_timer = 0;
4. public float GetTimer() {return m_timer;}
5. public void SetTimer(float timer) {m_timer = timer;}
6. ...
7. }

How do I access GetTimer and m_timer from entity?

 

Thanks for your reply,
I still have a long way to get the whole picture it seems.
I think I get the "conversion" part, from Monobehaviour to Entity : you create a struct with mirror values.
But how do you deal with your monobehaviour functions members? Do you transfer or copy them from your monobehaviour to your entity struct?