This kit includes everything you need to change the fluid in your GR6:
How to install the filters yourself:
Do you need a DRAG or ROAD RACE sump filter?
This is a data log of what a clogged line filter looks like. Note how line pressure (ORANGE LINE) drops off and can't keep up with target (BLUE LINE) at low pressure conditions:
Here is another data log of the same unit with the line filter replaced. Note how line pressure (ORANGE LINE) follows target (BLUE LINE) perfectly:
It's very hard to see the junk in the factory filter. Sometimes when they are cut apart it's shocking what is found inside, as you can see from this OEM unit below: