Combination Valve: Removal
WARNING: This page does not describe the selected car, but rather 30 other vehicles, including the 1998 Pontiac Trans Sport, 1998 Oldsmobile Silhouette, 1998 Oldsmobile Bravada, 1998 GMC Yukon, and 1998 GMC Suburban. However, it is still accessible from the selected car via links, so may be relevant.
Raise and support vehicle. Disconnect brake warning light electrical connector from combination valve switch. Disconnect brake lines from valve. Cap brake line ends. Remove valve mounting bolts. Remove valve.