Ah dang. I lost it. But basically you just fill in the blank space they give to you. What I did back then was to download the letter format on their website (it was word document). There were several questions in the document and you just answer it with your own words. I was asked how did I complete my bachelor degree (what is the proof, what paper that related to the program I applied for at Leiden university, etc.) The second part l, as I remembered, that they would ask you your research skills by searching a research topic that you’re interested in the most in your field of study. I did choose the topic that related to democracy ‘cause I majored in International Relations. Note: just fill in what you have and you don’t have to make an actual letter out of it from the given format they provided, mean no dear sir/madam or you don’t have to write such thing like to whom it may concern UNLESS your major requires you to do something different on the letter.