Examine the bracket holding the top rail between two end posts or support posts to determine the mounting system. The mounting screws may or may not be visible depending on the manufacturer. Some PVC railing systems use escutcheon plates that snap over the mounting brackets to hide the screws.
Slide a flat-head screwdriver between the escutcheon plates and the support posts if applicable. Twist the screwdriver slightly to unsnap the escutcheon plates and expose the screws holding the top rail between the posts.
Remove the screws holding the railing in the brackets. If your railing uses support brackets that snap over the ends of the top rail and attach directly to the posts, remove the screws from the brackets to release the rail.
Lift the top rail off the spindles. The tops of the spindles slide into openings cut into the bottom of the railings and do not require fasteners.
Pull the PVC spindle from the bottom rail. The bottoms of the spindles slide into opening cut into the bottom railing and do not require fasteners.