Until this past year, I had never moved a parts department. While we didn't move across the city, moving from an upstairs location to a temporary location downstairs and then back up to a newly remodeled area six months later, isn't easy.
As a dealer, be sure to include your parts manager and his staff in the process. Listen and understand their needs with relation to the new facilities. If you can meet their needs, do it. If not, let them know.
As a parts manager, make sure you have a plan of attack and a big enough crew to get the work done. Hire some extra help to move and assemble bins and use the parts personnel to stock and locate the parts. Make sure your voice is heard.
Otherwise be prepared for more tension than you can imagine.