2001 Kia Spectra transmission gasket leak

Which gasket are you wanting to replace?

The pan gasket, I believe

drain transmission if you have a drain plug on the pan, if not, undo at one end and keep a container under the pan, start undoing the remainder of the bolts and the pan will drop down a little and oil will start to drain, hold pan and undo the rest of the bolts, drop pan and clean, replace gasket and re fit pan torque bolts to around 10nm add correct oil as per manufacture's spec