Welcome to the site! As for your question, I'm not the most qualified person to answer this question (there are other people who know more about this stuff than me), but here you go.
Short answer: Sadly no. You have to delete all of them and start again.
Long answer: Sorta, but you're better off restarting because this solution probably even more of a hassle. Basically, there's at each link on the left a script button (the blue box one). Click on it. And enter this code. $DEST:=@P15
@P15 just means that it this link will go to page 15. If you want it to go to page 1, then change it into $DEST:=@P1 . The number of the page can be found in the advanced editor menu where you can see all the pages.
Then afterwards rename the link and bam you're done.
But honestly, starting over will probably save more time than this roundabout approach.