Hi hzambran (Mauricia).
I have to first understand if the issue is with the 5775 or the 7232. Assuming you are asking about the 7232 I looked at the WorkCentre 7232 knowledge base and found several solutions that focus on installing a printer but I think what will have what you need is in the System Admin Guide on pg 36. There you will find the instructions for Quick Network Setup. Below that are the steps for Manual Setup using Static IP Address.
Use this link to access the documentation section within Support. Scroll down to the System Admin Guide. It is a pdf so you will need to select it. When it opens go to page 36.
http://www.support.xerox.com/support/workcentre-7232-7242/documentation/enus.html
Let me know if these help.