how to restring ukulele with one hole slot bridge

Hello I have a rubin rp 400 pocket ukulele. There are single tie knots and a single hole in the bridge to restring. There is no hole at the top of the bridge to slide the string through. Can anyone help explain how to restring this ukulele?

Just checked a close up of an rp 400 bridge. The string slot is slightly larger where it meets the body. This is where the knot slides in. When you remove the first string, it will become clear to you.

Ok thanks I was just a little nervous about changing a string since the instrument is so small and possibly fragile I appreciate your response