Archive the entire project with 5.4.
Then use 5.3 to import and re-archive.
I dont think that will work for a V5.4 project. Best bet is to follow the advice of L D[AR2, p#0.0] and export as source code then import to V5.3. Export the Hardware from HW Config under the menu option "Station".
To export the code you must first generate a source file from the LAD/STL/FBD editor by selecting File - Generate Source. You will be promted for a file name so enter something like ALL.AWL. After accepting your file name, you will be promted to select files to add - select All and click OK. The newly created source file is located in your project in the source folder (above blocks). Open the source folder and export the file by right clicking on it and selecting Export source.
You also need to export your symbol file. From the symbol Editor select the option Symbol table - Export.
Import into V5.3 First import the HW Config into a new project then open the new project. Import your symbol table to the new project using the Symbol editor.
To import the code, right click in the source folder of the new project and select Insert New Object - External source; select your previously exported All.AWL file.
To generate the blocks, the source code must be compiled; right click on the source file and select the Compile option. Pay attention to any error messages that may appear at the bottom of the screen. If there are no errors then all of your blocks should now be in the blocks folder. N.B. after compilation, all blocks will display as STL, using the editor you can change to your preferred view.
Nick