yer so funny
I want to tell you how simple it is to change the filter and gasket, and to look at the front of the torque converter for a small bolt in the front of it for a drain, but tact will also tell you about maybe doing some simple band adjustments and maybe other stuff.
But go get a filter and gasket for your 904, get the car up on jack stands and make sure you are secure from the car falling on you. Have a big drain pan ready, look at everything around the trans for leaks like selector seal, rear tail shaft seal, tranny lines , dip stick , get a good visual of any place that has been seeping.
I usually start by undoing the 1/2" bolt heads from the back. So when everything is loose the front bolts let the pan tip to the black, allowing to control the trans fluid to some degree . The filter will have 3 screws holding it on in a SPECIFIC way. It only goes on one way to be correct. Clean the pan, replace the filter, after tact gives you some pointers. It will take close to 5 qts to refill it up if you didnt drain the converter.
When checking the fluid, the car needs to be running and in neutral. Always put the car in drive before reverse. I have left some stuff out but just got you getting a dable of what to expect. It will be easy
I use no silocone and dont over tighten the gasket, it will leak
