Interview Help

I am recruiting internally for a position within my Customer Service Team. Two people currently working in the team have applied and as one has recently been interviewed by me for her current position I want to do something different for these interviews.

I have been thinking of getting them to present to me why they are the best person for the job based on the jobs competencies.

The thing I’m stuck with is how to word the interview invite letter. I have no HR dept and I’m floundering round on my own!

Has anyone got some advice or examples.

Thanks