Assuming no other complaints you would only need to change water to lower the total dissolved solids level or cyanuric acid level. TDS should be below 500ppm and cyanuric acid ~50 ppm.
weekly
Passwords should be changed every month.
According to my dealer, it should be changed at 150,000 km.
When it is dirty.
When it is dirty.
When its old
weekly
If you do not drive it often, I would recommend getting it changed every 3 months. That is what many mechanics tell you to do.
30000 miles
The engine oil should be changed every 3000-5000 miles
Every six months
Every 96 hours