Have sorted this myself a few times.
Step 1: Replace cabin air filter
Step 2: Vacuum really well
Step 3: Clean all fabrics with detergent (wet clean with a wet vac to suction off moisture after) including seats - it’s imperative the seats are done if fabric
Step 4: Steam clean all surfaces
Step 5: Deodoriser can
Where are you based? If local I’m happy to give this a go for you (for free of course!).