How to delete an activesync partnership

Over time users buy new phones, add tablets or Windows 8 mail apps to their corporate mail.
This clutters the ActiveSync partnership as only 10 devices are max supported.

This shows how to delete the unwanted ActiveSync partnership(s).

Get-ActiveSyncDeviceStatistics –Mailbox alias | Format-Table DeviceID, DeviceType, DeviceOS

Output:

DeviceID                          DeviceType    DeviceOS
--------                          ----------    --------
Appl82XXXXT6A4S                   iPhone        iOS 6.1.3 10B329
XXXX99427EA69C4070E3A9FFA5D7EA84  WindowsMail   WINDOWS
XXXX59A3A6CE935CA7A176D6616793E2  WindowsMail   WINDOWS
XXXX66426C02FEFAD9A8E189F7CB4746  WindowsMail   WINDOWS
XXXX1D99A11C747C075A0828FD1F0358  WindowsMail   WINDOWS
XXXXF213DACD1001CA7B97AF346F4C47  WindowsMail   WINDOWS
XXXX6F8CDBB2D75B3C32898543996CAB  WP8           Windows Phone 8.0.10211

Delete the Windows 8 Phone:

Get-ActiveSyncDeviceStatistics -Mailbox alias | ? {$_.DeviceOS -match "windows phone 8.0.10211"} | Remove-ActiveSyncDevice