The attribute that controls where the process alarm is asserted is the PMon_SendAlarmsTo attribute id 0xc4112b on the Host Resources application model of type rfc2790App associated with the device model. So, to do this in bulk:
1. Run a Locator search to find all Host Resources application models of type rfc2790App
2. Select all of the models in the Results list
3. Right mouse click on any one and select Utilities -> Attribute Editor from the menu
4. You will need to find and select the PMon_SendAlarmsTo attribute id 0xc4112b under the User Defined section
5. Un-check the No Change check box, set the value to Device and then check the Set As Default check box
6. Click the Apply button
This should set all current process monitors to send the alarm to the Device model as well as all future ones since the default was set to Device.