Hi Kable991,
If you have you have AVI console linked with your vCenter you can resize the Service Engine using the AVI console under the Service Engine Group section, in this case you must have an enterprise license.
If you don't have AVI console linked with your vCenter you can't orchestrate it automatically and you need to do it manually. You must shut down the Service Engine appliance, resize the resources as needed thorough vCenter and power on it again.
Here some useful doc links about SE resources best practice:
https://avinetworks.com/docs/latest/se-memory-consumption/
https://avinetworks.com/docs/latest/sizing-service-engines/
https://avinetworks.com/docs/latest/service-engine-group/
Best.
