Replacing array data

What is the correct syntax to replace array data? The array is spawned from UDT, trying to replace some baseline values. Appreciate any help.

tagPath = “COATER/Historian_Data/RECIPE/CTR_REC_IMPORT_ACT/CTR_REC_IMPORT_ACT/INT1[3]”

tagValueArray = system.tag.read(tagPath).value
tagValueArray.append(“COATER/Historian_Data/RECIPE/7282-1830/7282-1830/INT1[8]”)

system.tag.write(tagPath, tagValueArray)