How does one change the transmission fluid? Kia Rio 2003 on 2003 Kia Rio

For some years now before the engine is warm the car has difficulty getting in gear, particularly in reverse. I suspect a transmission issue but we have been able to drive the car for 3 years without a repair.

Asked by for the 2003 Kia Rio
1 answer
have it done by a pro. most are drain and fill but some are more difficult these days. having it done is money well spent to make sure its done right