To add or remove units to/from a retranslator, use the command retranslator/update_units:

svc=retranslator/update_units&params={"itemId":<long>,
				      "units":[	
						{
							"a":<text>,
							"i":<long>,
							"st":<uint>
						}
				      ]}

{
	"rtru":[
		{
			"i":<long>,	/* unit ID */
			"a":<text>,	/* hardware unique ID */
			"st":<uint>	/* time, when retranslation will be stopped */
		}
	]
}