At the bottom of the transmission unbolt the pan and completely remove the old gasket from the rim then replace it with the new one. You'll need to be careful of the oil spilling out when unbolting and I would replace the fluid and filter while you're at it. The filter is on the bottom of the trans enclosed by the pan.
There is no reservoir.
colourless.
transmissiom fluid for 2001 kia optima 4 cylinder
A transmission fluid leak means that the plug may need to be replace, or the seal or gasket may need to be replace. As it could be caused by a work seal, or gasket, or a loose plug.
Remove transmission oil pan for acces to filter Replace fluid, filter, and gasket
Remove the transmission oil pan for access to filter Replace fluid, filter and gasket
Remove the transmission oil pan for access to filter. Replace filter, fluid, and gasket.
Remove transmission oil pan Replace fluid, filter, and gasket
Remove the fill plug from the 2001 Explorer differential. Remove the cover from the head to allow the fluid to drain. put the cover back on with a new gasket, then fill the unit up through the fill hole.
All you can do in your driveway is drop the trans pan, replace the trans filter, replace the trans pan gasket, install pan (no gasket sealer needed or required!) and refill what fluid drained out in the process which is aprox half of the fluid the trans holds. Take it to a trans shop if you want a complete fluid change. They will have the equipment to do a trans flush.
Make sure you have the right transmission fluid. Changing the fluid will require removing the bottom of the pan and draining the fluid. You will need to replace the pan gasket and it is a good idea to replace the filter. There are kits available with the required parts.
That is a scary situation. The best, and cheapest, thing you can do is immediately replace the gasket. You can keep driving it with a slow leak, but you will have to keep putting transmission fluid in it. Which will cost you more in the long run. If you replace that gasket now, You won't have to worry about constantly re-filling the transmission fluid.