If i didn’t have a soldering iron, I’d probably grab a diode or resistor leg and snip it just enough to bridge the gap and press it down on the contacts and use super glue to hold it in place until it held and hope the glue doesn’t block the contacts.

But this is an extremely shoddy solution and i doubt it will last long. A soldering iron for students can be pretty cheap and I’m only suggesting this alternative so you have some sort of solution that doesn’t involve one.