1) Send ZDO Leave to ZR parent with ZED's EUI as target 
-Pros: Will always succeed (if ZED is still in the child table of ZR and ZR is reachable) with response status, regardless of what ZED's polling rate is. 
-Cons: If ZED isn't polling parent regularly, parent's NWK Leave command to child could time out before child gets it, and child gets erased anyway. When child polls next time, parent will tell him to leave and rejoin because it's an non-child end device, so that gets you back to before the ZDO Leave. 

2) Send ZDO Leave to ZED with ZED's EUI (or all-zero EUI) as target 
-Pros: ZDO response clearly indicates whether ZED received the leave request. No confusion as above with ZED accidentally being told to rejoin. 
-Cons: If ZED isn't polling parent regularly, it won't receive this request, so sender needs to be careful about timing of sending the request.

3) Send APS Remove Device command to ZR parent with ZED's EUI as deviceToRemove. 
-Pros: APS-authenticated (unlike ZDO messages), so devices (even SE devices) can't choose to ignore this, and it is harder to spoof because it requires APS encryption. 
-Cons: Need long address of child and parent for the command. No APS ACK available for APS commands, so can't confirm receipt by the parent. Still may encounter problem where parent deletes child before the child knows it was removed, causing child to rejoin on next poll attempt. Can only be sent by Trust Center.