Don't push the ring collar into the pump connector with too much force. If it's hard to remove the ring collar for cleaning, first hold the parts under hot running water and hopefully the plastic will soften just enough for you to twist the ring collar out from the connector or rock it back and forth a little until it pops out.
Pulling the collar straight out from the connector does not work well.
If the ring collar is still stuck, try using a pair of pliers to hold on to the small tabs on the outside edge (it will do less damage to the tabs if you protect it with a piece of soft material like a towel) and twist the collar ring out. If nothing budges it, let us know.
Reviewed by Diana West, IBCLC
June 10, 2021