Translation of una vez

In order to change something you need to have courage, even if it is the smallest thing. Actually let me refine, changing needs only courage if the current situation is not bad but not perfect either.
She even compares the hills across the station with the belly of a pregnant woman by saying that they do look like white elephants. Maybe she thinks that way but I am not really sure about that.
I called the Hilton hotel in Cuba and asked them whether it was worth coming or if they suggest to postpone the arrival. Their response was clear: Don't come unless you really have too.