Renewing your visa in Egypt is an interesting experience, to say the least. Many students will have stories to tell about their experiences, as it is not always an easy process, but with the right amount of patience and determination, it can be (and is) done.
There are various resources online with information on renewing your visa, however the processes change frequently and it is sometimes dependent on who is at the window when you are renewing.
One online resources you can refer to is: http://lauratraveler.net/2017/01/how-to-renew-your-tourist-visa-at-the-mogamma-updated-december-2016/
Always be aware that every experience is different and what applies to one person may not apply to the next. The process of extending your visa can take 2 days to complete.