Foud Bhae, You dont need to open the chamber. The pan has a screw, And a L Nut (L-Key Screw) the entire oil comes out. Since you can never take out the entire oil becasue most of it is in the transmission. It is not recomended to open the chamber and replacing the gasket.
We refilled it till the pipe started over flowing. Did this around 62,000 kms, The cars around 105,000 now.