Mark the rail height on the wall against the lowest step. Hold a spirit level flush against the wall and center its bubble to ensure the mark is level. Repeat this process on the highest step.
Snap a chalk line between the two marks along the stairway to create a sloping line on the wall along the stairway.
Assign two helpers to hold the rail against the brick wall, aligned with the chalk line. Insert the tip of a paint marker in each mounting hole on the rail to transfer their locations on the wall. Set the rail aside.
Measure an anchor’s length with a measuring tape. Wrap tape around the masonry bit at the point that matches the anchor length, so you know when to stop drilling. Alternatively, use a masonry bit that matches the length of the anchor.
Drill a hole at each marked location on the wall for the mounting brackets.
Insert an anchor into each hole. Tap the anchors lightly to drive them into the holes, until their tops fall flush with the surrounding brick surface.
Assign a helper to hold one end of the rail while you hold the other end. Align the rail against the wall so the holes for the mounting brackets match up against the anchors you secured.
Drive anchor screws into the anchors using a screwdriver. Turn each screw clockwise to tighten it, until it its head falls flush with the surrounding wall surface.