You can modify individual reminders to alter their delivery schedule, or you can delete each to stop them altogether.
A short-term workaround is to deselect all the days for the reminder you want to pause. This effectively means that it will never be sent to you. When ready to turn it back on, edit again and add the appropriate days back.
A future feature will be ability to pause a reminder and then the ability to re-enable.
If you want to stop the service completely, log into your account, go to the Profile, then the Billing subsection, and use the "Cancel subscription" link.