I am trying to replace the filter in my WMC F600 filter and thought I was all ready to go. I have my 300 lbs of sand (the filter holds 260), my multiport is attached with unions so no need to cut anything, and I drained out the water in my filter after turning off the pool circuit breaker. Thing is I can't figure out how to remove the multiport to get at the sand. There is no collar at the top of the filter. Any advice? Please let me know if you need better images or different angles.