I have 168,000 on my 1999 E 430 I think these are great caes its my first Benz

 

I have a 1999 E320 wagon with 224,000+, no major work done. I have a day and a half looking for an answer on this forum and haven't found it yet. The center brake light on the tailgate needs replaced and I need some instruction on how to do it. I tried a number of searches to no avail, can someone point me in the right direction? Please and thanks in advance!