You can use SNMP manager (that is one of Extreme Management Center imminent features, or some standalone thing to modify MIB content on a device), or you can try CLI/TCL scripts (that will be put manually through SSH or via NMS software like XMC), or Python scripts (that can be put and executed on EXOS as a one shot or as a process), or JSONRPC, or (quite fresh - since 22.4) RESTCONF (kinda similar to NETCONF, there is YANG model etc.). You might find this useful:
https://api.extremenetworks.com/
Regards,
Tomasz