Find and replace text problem in Photoshop

You need to do basically 3 operations:

• traverse through the layers and select them one by one;
• replace a part of the layer name using a regular expression pattern;
• rename the layer with the new name;

A basic* version of this could look like this:

var layer;

// looping through top layers
for (var i = 0; i < activeDocument.layers.length; i++) {
  layer = activeDocument.layers[i]; // for ease of read
  activeDocument.activeLayer = layer; // making the layer active
  layer.name = layer.name.replace(/@.*@/,'##'); // replacing the layer name. @.*@ regex pattern will select anything between two @ symbols
}

Update: replacing the layer text contents.

Basically the same thing with some additions. You need to check if layer.kind is LayerKind.TEXT and instead of changing layer.name you need to change layer.textItem.contents

*. note that activeDocument.layers collection contains only top level layers. If your document has groups (aka folders) or artboards you'll need to go through nested layers with a different function: something like this

I tried myself with the script below, it does works, but don't know if there is any structure I missed:

var layer;

// looping through top layers
for (var i = 0; i < activeDocument.layers.length; i++) {
  layer = activeDocument.layers[i]; // for ease of read
  activeDocument.activeLayer = layer; // making the layer active
  layer.name = layer.name.replace(/@.*@/,''); // replacing the layer name. @.*@ regex pattern will select anything between two @ symbols
  layer.textItem.contents = layer.textItem.contents.replace(/@.*@/,''); // replacing the layer name. @.*@ regex pattern will select anything between two @ symbols
}