The Collaborative International Dictionary of English v.0.48:

Declass \De*class"\, v. t. [imp. & p. p. Declassed; p. pr. &
   vb. n. Declassing.] [Cf. F. d['e]classer.]
   To remove from a class; to separate or degrade from one's
   class. --North Am. Rev.
   [Webster 1913 Suppl.]