Help can be found for adjusting tray alignment in the Xerox Online Support Assistant here on Xerox.com. The knowledge base articles contain step by step instructions to help resolve problems. Follow the link below and enter "Xerox 700" in the search field but do not hit enter until you highlight the first result of the search which should be "Xerox 700 Digital Color Press." From there, select which configuration you have and click the corresponding "Support" link.
Once the Knowledge Base opens, type "tray alignment" in the search field and click the search button. Hopefully this helps to resolve your problem. If not, at the top of the knowledge base window you will find the 800 number for contacting the Xerox Customer Technical Support (800-821-2797)