Pick a bigger topic
Six pages is approximately 1500-1800 words. Pick a bigger topic. Find a great deal of research. Do write in a concise way, but fill the pages with details, reasoning, and analysis. Don't think of it as a longer paper, but as a deeper paper, with a wider base of understanding to be displayed to your instructor.
Aside from this, a 6 page paper is written exactly the same manner as a 2 page paper. The difference is that instead of developing a stage in one paragraph, you might have to spell out the finer details in greater depth, with several paragraphs.
I propose making an outline or a mind map so that you are able to capture and organize your thoughts in your native language before you begin writing. Then you can focus on obtaining the info in good order before you start massaging it into English.
Do not write long, fuzzy paragraphs, because that will not improve your quality. Don't be repetitive. A long essay needs more substance, so do more study and do more considering the context and the meaning of this topic.