You should be able to modify the WINS info from the Embedded Web Server (EWS). I know the removal steps below do work on one of my CP3525, but I can try some other models if necessary too.
Remove the WINs (CP3525):
1. Enter the IP Address of the printer into a web browser
2. Sign in if you have that feature enabled
3. Click the networking Tab
4. Click TCP/IP Settings
5. Click Network Identification tab
6. Delete the WINS primary and secondary fields under IPv4 Only
7. Click Apply
If that setting is not sticking or is incorrect then you may have to perform an NVRAM Initialization/Cold Reset. A reset of this level removes all of the network configurations you made to the printer. If the printer is still pulling in an incorrect WINs after performing the reset then something is passing along that info, perhaps during the DHCP registration process when it first connects to the network.