I have a reservation but the time of arrival of my flight has been modified. I will arrive four or five hours later on my destination. Am I supposed to cancel the existing one and make another one ? or can I keep it? Thank you, Nori

As long as they know you are arriving but later time it would be ok. No need to change your reservation.

Call them and let them know of the change in your pick up time

Call them asking for updating pickup schedule. You'll get a confirmation e-mail from Enterprise.

Maintain it. I've called them and advised them of my delay for that extra peace of mind.

Keep it