Currently we have a check for a Cisco ASA 5500 Series for Firewall CPU Utilization.
Currently the SNMP OID is : .1.3.6.1.4.1.9.9.109.1.1.1.1.5.1 by default
The check it is coming back with is; 

"Firewall CPU Utilization is 4294962%, threshold value for this monitor is 60%"

We have identified that the correct OID for this is actually 1.3.6.1.4.1.9.9.109.1.1.1.1.8
What is the best way to change the OID for the check on this device?