So i wanna change my oe bov to a hks. What are the proper steps in order to do this.And does my car need to be slightly tuned for this in order to work right ?

 

Already a lot of threads on this.
If the HKS is recirculating back into the air intake then no tune is needed.
If the HKS is vent to atmosphere then a tune is needed because the Mass airflow sensor is expecting the return air.