Remove the bottom faom pad, which should just be held on with phillips screws. Under this you will see the eccentric weight that has a screw in the middle. Not sure if it is left hand thread or not so be carefull. It is normally thread locked aswell so be firm but fair when unscrewing it. Once it's out you should be able to lever the weight of by applying equal pressure to each side of it. It will be centered on a woodruff key so be cartefull not to lose it. Also, in between this part of the base and the main body of the machine there is a rubber skirt that is clamped to both parts. Unscrew the band clamping the skirt to the base and I think you should be able to pry it apart then.