Good advice !

OK I just did this with my red dualsense and it was actually easier than this. Maybe it is a newer version??? I don't know, but it is different.

If you have the same one as me then do all steps up to, and including, step 18. Then do steps 23 and 24. Remove the two screws in step 27. All the guts will then lift out of the plastic shell, leaving you in a similar situation to step 29.

However, step 11 was difficult for me as the two parts did not simply pull apart. The bottom half came apart easily, but I had to push a thin tool in the top part near the trigger to release an extra clip. Only on one side, then the other side was easy.

Have fun!