Any tips for writing a cover letter for your own job?

When a person becomes benefited, the university I work for requires that you submit your resume and a cover letter, and they’re required to post the position, even though as in my case they aren’t going to interview anyone else (I don’t even need to be re-interviewed, actually) and it’s classified as internal anyway.

I’ve been told by my grandboss that I should be able to “apply” for my job later this week. I’ve polished up my resume to my satisfaction, but now I’m thinking about the cover letter I need to write. Even though it’s all a formality, I don’t want to appear to blow it off.

So does anyone have any tips for writing a cover letter for a job you’re already doing? How should it be different from a cover letter written for a job you’re hoping to get at a company/org you don’t already work for?

Discuss your experience with the job and its duties under your current job title. Discuss your satisfaction. Omit any reference to interviewing, being appointed, etc.