How to remove dashes only from the line in RegExp?

HKCU\Profiles\0\lines to modify " -a -b -c"

ex.

HKCU\Profiles\0\lines to modify " -a -b -c"
HKCU\Profiles\0\line line unchanged " -a -b -c"

it should be

HKCU\Profiles\0\lines to modify " a b c"
HKCU\Profiles\0\line line unchanged " -a -b -c"