Datasheet

down

Once you have that working, you can solder wires to the Pot Vol pads, so you can place the volume adjustment pot

elsewhere (say mounted to the outside of a box)

If you want a potentiometer that will fit exactly in the slot, check out this side-adjustment pot

http://www.digikey.com/product-detail/en/bourns-inc/3362M-1-103LF/3362M-103LF-ND/1088401

For mounting onto a box or panel check out https://www.adafruit.com/products/562