Can I change Priority Names once live?

Can the Priority names be modified once records have been created using those priorities? For example, we had someone configure ME for us and they used 1 - System-wide Outage and we want it to be 1-Any Outage. Can I do that? Does ME use and store foreign keys to represent the priority and in turn the Name will be polled separately when presenting data in lists and on reports?

Hopefully, this makes sense...I need to change the Name text of our priorities...can I? Is there a list of what other values I can and cannot change? The Model shows a PriorityDefinition table with PriorityID and PriorityName fields...so, I'm hoping I can make these changes. Thanks