Hi Chango -
Easy. There are essentially 2 ways to do a delete: In-Memory, or Immediately.
If you want to do an immediate delete. Do myEntity.Delete().
If you want to delete in-memory and commit it later - you will want to use the myCollection.RemovedEntitiesTracker. So, whenever you do myCollection.Remove(myEntity)... myEntity will be automatically removed from myCollection and will be added into myCollection.RemovedEntitiesTracker.
Then, when you're saving - simply do: myCollection.RemovedEntitiesTracker.DeleteMulti().
Hope this helps!
Ryan