Either demolish the wall.
How to fix a leaning concrete wall.
Screw an anchor rod through the hole.
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 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.
Using anchors drill a one inch hole unless otherwise specified by the wall anchor manufacturer in your retaining wall.
Straightening the wall will require some engineering and is beyond strangers on the internet.
When this occurs the homeowner has two choices.
Something in between could be addressing the drainage behind which could help prevent further leaning.
This mortar is typically one of the first things to show wear on a well made wall.
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.
Install the wall plate and tighten the anchor rod.
Solution 2 wall anchors concrete retaining walls can be reinforced with wall anchors from matthews wall anchor waterproofing services.
So a totally proper repair would be to remove the whole thing and start over.
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.