To stop a membership, you only need to stop recurring payments and their membership will be terminated after the next Renewal due date and after their grace period.
The button to stop recurring payments is highlighted in the attached image. If such button doesn't show up in the member entry, it is likely the member has already stopped payments by themselves.
This process can be also accomplished by the members themselves. Visiting their profile in WA and going to Invoices and payments and clicking in Stop recurring payments.
