I might be wrong, but only the oil reservoir has a bottom outlet. You can unhook that and drain the oil out that way...I siphoned out as much as I could get flowing out of there and then pulled that oil line off the bottom nipple and put a 7-11 slurpee cup down there to catch the oil from the bottom.
But as far as the gas tank...Pretty sure the only openings are on the top of the tank (connection for where you fill the tank and where the baffle goes)
I attached the fuel system diagram for your fuel system. Taken from bikebandit website.
For me...I removed the clamp for the large black "filling tube" and gave it a good tug to remove and then siphoned it out through that hole. If you want to remove your tank, you should be able to remove both the baffle and filling tube and remove it through your front compartment. Atleast thats how my 97 was.