Take it to an interior detailer who does a thorough job , my guy when i am too lazy takes the front seats out an all. As well as using a bio chemical mixture to break down smells and dirt ( probably pine-sol ) but it works great and does not smell.
Other than that buy an auto ionizer and leave ti plugged in 24 hours a day for about a week and it will reduce the smell ,but to remove it totally it will need cleaning.