If your transmission fluid needs to be changed, then you need to know how to change transmission fluid on a Honda Civic. Hondas are reliable cars that require regular maintenance. Changing the transmission fluid is part of the maintenance that needs to be done either every 90,000 miles or every 72 months. Remove the jack and jack stands from your Honda Civic. 2  Use the dipstick to check the transmission fluid level to make sure you added enough. 3  Start up the car and run the engine for about 20 minutes so it can reach its normal temperature. 4  Check the fluid level again. 5  If needed, add more transmission fluid.