hi Sylion:

As far as I know, it's NOT possible to move, delete, or change 'chord name' data from within the Yamaha arranger keyboard itself.

The ONLY way you can edit the 'chord names' (Yamaha XF data) is by loading a PSR2000 produced song file (.mid) into the Yamaha proprietary midi sequencing program called XGWorks:
http://www.yamaha.co.uk/xg/html/midplug/m_mid10.htm

Yamaha arrangers (PSR2000, Tyros, 9000pro, etc) utilize auto accomp 'chord data' only recognized by Yamaha's "XGWorks" software. Currently no other midi sequencing programs (Cakewalk Sonar, Logic Audio, Cubase, etc)recognize Yamaha exclusive XF Meta Event data, though there is rumor that a software 'plug in' is currently being developed for Cakewalk Sonar which will add 'XF Meta Event' support Sonar sometime in the near future.

With XGWorks, the auto accomp 'chord names' (C7, F7, Cm7, etc) is displayed in a separate track (alongside the other standard midi tracks), and you can edit the chord name, move the location of the chord, or delete the chord name event entirely.

Hope this helps.

Scott