Updating woocommerce stock manually

Hi.

I am looking for advice as to how how I update stock manually in Woocommerce.

I retrieve a CSV file from my supplier via FTP, and I would like to process stock updates.

I am not a PHP programmer, however I have managed to write a script and update the database directly, however I have been reading that this isnt the best way as i am updating columns such as “_stock”

I would like to be able to write a plug-in and do it properly but havent got a clue where to start.

Any advice would be greatly received.
regards
Steve