Hi John Benedetto,
If you simply set the print devices to inactive (Output Management > Devices) they will not count against your license. That said, even with a stripped down license, your SignUp server services will still run - it is just the print server service that will not. The downside is that you have "red lights" in your list of servers, but the good news is that you keep all your transactional data. In 9.1 Pharos allows you make an server inactive which alleviates the problem you are facing, but I am not sure which version of Pharos you are on.
Disclaimer - There is no easy way to simply undo the removal of transactions from the database. Please backup your database first and proceed at your own peril.
If you do not care about any transactions of any kind - print or SignUp (i.e. computer usage history and statistics), then simply archiving all transaction and alerts should just about get you there so you can delete the server. Under transactions, you can pick a date range or select all transactions. All means ALL from all time and all types, and the date range does the same save for narrowing it down to a specific range of time (all transactions of all types between two dates will be removed). The same logic is true for archiving alerts; there is not a way to get more granular regarding what is removed (e.g. print transactions only).
Since everything SignUp related will still work, there isn't really a pressing need to change anything at all unless you just want to make sure the servers do not show up as red.