  We find an explicit form for the Jacobian of arbitrary field-dependent BRST
transformations in Yang-Mills theory. For the functional-integral
representation of the (gauge-fixed) Yang-Mills vacuum functional, such
transformations merely amount to a precise change in the gauge-fixing
functional. This proves the independence of the vacuum functional under any
field-dependent BRST transformation. We also give a formula for the
transformation parameter functional which generates a prescribed change of
gauge and evaluate it for connecting two arbitrary R_xi gauges.
