tracylou,
Here is a link to the Manual for the S210T. The plumbing to and from the filter will determine how hard it will be to remove the multiport valve. Once the plumbing is disconnected, remove the two screws on the flange clamp (loosen each one a little at a time) and remove the flange clamp. Gently turn the multiport to break it free from the filter body and the internal pipe then lift it off. When reassembling, carefully clean the O-ring and the seating surfaces on the filter body and the valve body. Some people (me included) use siliconed O-ring lube to help seal the flange and make it eaiser to open the next time.