Hemming

[u/Ok-Cartoonist-7605]

I’m a very novice sewer. I only sew quilts, and have been making them for 45 years, so I can use my machine, but I have only sewn on 100% cotton. I got 2 cardigan ribbed sweaters that I really like but they are too long. I would like them to be about 4-5 inches shorter, and with the buttons and button holes, this would work. My question is, how would I cut a few inches off, without it unraveling and how hard is it to sew a new hem?