My 96 Sunfire has no red cap, it has a regular dipstick. You'll want to find a small funnel. The fluid goes where the dipstick is supposed to be. I would also go to the parts store and get a new dipstick.
Through the automatic transmission dipstick tube with a funnel
Automatic transmission oil filters ware located inside the transmission, under the transmission oil pan. You have to remove the transmission oil pan to replace it and then you will need to refill it with new transmission fluid.
The automatic transmission will hold almost nine quarts.
For automatic trans you refill the fluid thru the dipstick and for manual theres a fill hole in the tranny..
To drain and refill it takes 2.5 quarts of Mercon Automatic Transmission Fluid.
automatic transmission fluid, ATF
if it is a automatic transmission you should change it every 15,000 miles, and if its a manual its recomeded at 30,000-45,000
7.4 Quarts Application: With automatic transmission Total refill (includes torque converter)
Fluid capacity depends on the transmission on your vehicle, it should be stamped on the transmission pan. 4L60-E Automatic Transmission Drain and Refill 4.7 Liters (5.0 Quarts) Overhaul 10.6 Liters (11.0 Quarts)4L80-E Automatic Transmission Drain and Refill 7.3 Liters (7.7 Quarts) Overhaul 12.8 Liters (13.5 Quarts)
8.6 Quarts With automatic transmission Total refill (includes torque converter)
Drain and Refill Automatic Transmission Fluid - Volume: 3.20QTS. ( 3.0L )