Adding extra room to leg openings

I need to add more room on the leg openings for my new pants, but I dont want them to rip, how should I do that?  Obviously I need to cut them, but how should I keep them from continuing to rip up the leg.  I dont  have or know how to use a sewing machine, so thats out, would super gluing along the cut and at the top work?  How have you guys done it?

Any help would be much appreciated.  Keep in mind the pants only cost me $10 but I still dont want to just straight up destroy them.

Thanks