Either demolish the wall.
How to fix a leaning concrete wall.
In a brick and mortar retaining wall the bricks are secured together with a layer of mortar which looks like a light gray concrete.
If the wall has moved significantly the soil outside the wall will have to be excavated and the foundation wall straightened or in the worst cases replaced altogether.
So a totally proper repair would be to remove the whole thing and start over.
If the movement is minimal carbon fiber straps or steel wall braces are an appropriate repair to prevent further movement and the possibility of having to excavate and straighten the wall later.
To fix the mortar carefully chisel out mortar to a point of a little over 1 2 the depth of the brick.
Wall anchors can be a long lasting solution to strengthen retaining walls and actually pull them back as close to their original position as possible.
Screw an anchor rod through the hole.
Straightening the wall will require some engineering and is beyond strangers on the internet.
Make sure that the rod connects to the anchors that are installed within the soil.
Using anchors drill a one inch hole unless otherwise specified by the wall anchor manufacturer in your retaining wall.
Install the wall plate and tighten the anchor rod.
Retaining wall repair options whether a retaining wall is built of stone block concrete or wood it can begin to lean.
When this occurs the homeowner has two choices.
Solution 2 wall anchors concrete retaining walls can be reinforced with wall anchors from matthews wall anchor waterproofing services.