PS script to change printers and check for default

Question

 We have a large project of renaming printers due to some linux devises that do not agree with our naming convention. I am new to ps so looking for some direction.
Our current printers are say 'print$1' and we are changing to 'print1' basically just removing the dollar sign.
We have batch files for the helpdesk for new imaged machines so they will get the new names, no problem but for the people that have been here, how can I create a script that will do the following:
1. allow me to put old printer > replace with new printer
2. detect if old printer is default and make new printer default.
3. only affect the printers that are currently installed on the pc
note we have multiple locations and alot of print servers. 
thank you for your help

Answer 1

gaff-
I believe he wants to rename the printers on the client workstation. Group Policy can do that very easily
You can also add to your ProintManager script to have it generate the GP objects and add the users or computers to them.  Most of the time is is easier to just use ProntManager GUI unless you have hundreds of printers  If it is only a dozedn then
a non-scripter would be better off running the GUI.
We moved about 30 printers for 100 accounts in about one hour the first time we set up PrintManager.  This included an upgrade to 64 bit drivers which was the biggest issue. A rename is very much easier.  I can rename 30 probters with the GUI in
about 2 minutes.
It is resetting the client systems that is the issue.  If they are beoing set by GP or through a login script then this, too, is easy.  If they are just attached in different ways then I recommend that Group Policy is the only way to reset them
without spending a month trying to design a script that will work for all systems.
If this is for a WS2003 spooler then you can still use Group Policy Preferences it you install the AD updates or have WS2008 domain controllers.
Placing all printers under PrintManager control is the absolute best method.
If all printers are not Windows printers - (Unix spolers or JetDirect/Network) then you will have to create a script that can find every pronter and rename it on every system.  This will be very difficult to do and will likely take quite a while to
accomplish in a large network.
GP can install printers at the machine level and update drivers.  This will work well except if you are using non-Windows compliant printers.  I have never had this scenario work smoothly on  an older network.  This is one reason why
I do everything I can to force Admins to use PrintManager for all printers WIndows and Unix.  We also try to be sure the location awareness is enabled and that all locations are tagged in AD.  This allows users to browse easily for local and remote
printers.  We set initial default but user4s are always allowed to change the default if they want and know how.  Users are allowed to print to all "group" printers and departmental printers but not to personal printers.  In some cases
all users in a group can print to each others personal printers.
I am now working on getting wireless printers set up for use by visitors, guests and salespeople.  Every group should have a wireless printer and know the hidden SSID.  I notice that many universities and hospitals are now doing this for the convenience
of visitors. I can priont from my phone almost everywhere I go lately.
Use PrintManager.  It will save you a lot of trouble.  Once set up PowerShell can script everything very nicely.  Gaff's code will always be the easier way to do most things.
If you look in the repository/Gallery you will see many PowerShell PrintManger scripts and tools. -
I should also note that Gaff's suggestion to use WMI will only work in a login script and will not work well on system connected printers which will have to be done remotely.  Again, it all depends on how your environment is set up.
¯\_(ツ)_/¯