Polaroid 25-50 power zoom lens 7500Zix

I bought it at a rummage sale out of box - No instructions. It won't open on bottom where it says to open. Has battery-DLCR2 3 volt. Same switch on backside above window has arrow that points to C, H, or P. Small window is space to program: date, sel,set on the side and bottom of window looks like a timer symbol, another symbol in the middle and then mode. Maybe the area won't open because the film hasn't been used that might be inside. Also on back are two oval buttons with W on one and T on the other.The flash light comes on red, so I think the battery is good, but when I press bottom on top nothing happens. Can you help?