How to post pictures on Instagram from iPhone when the top part of your screen doesn't work?

So sometime over the summer, the top part of my screen became unresponsive on my iPhone and I can't replace my screen at the moment… And I'm like a HUGE Instagram-er and I'm missing it like crazy! And I was uploading pictures using my tablet but I don't have that anymore and I need a way to upload pictures and I was wondering if there was a way that I could post using my iPhone with it's messed up screen? Anything that could help me out?!

You don't, obviously you have to use the screen.