A protein deubiquitination process in which a K63-linked ubiquitin chain, i.e. a polymer of ubiquitin formed by linkages between lysine residues at position 63 of the ubiquitin monomers, is removed from a lysine residue in histone H2A or the variant H2AX.
Source:PMID:19202061,
PMID:19214193,
GOC:mah