05 H2 Lift gate- License Pocket Replacement

[The Ledge]

Someway, somehow, the top right hand corner of my rear license pocket was pried apart through vandalism or some other unexplained occurence. There was no evidence that a wedging tool was used to pry apart for there were no scratches on the top right corner of the chromed license lamp overhang piece nor were there any signs of paint scratches around the surface of the body along the edges of the license pocket. It appears it was pried apart through just fingertips.

Now is a good a time if any, to replace this part for it comes with the option without chrome and I do not want rain water to seap through to the interior of the lift gate. I found what I believe to be the replacement part(s) below:

https://www.hummer-parts.com/oe_parts_catalog.html

Is there anyone out there that has done this replacement, please tell me how labor intensive this is? or what part(s) I may still require besides what is illustrated for parts #3 and #4? Would appreciate any help online or offline regarding the parts or procedure. Thanks in advance.

Ed