This is a variation on the 5-hour baby sweater which I've made many times. You could cut the yarn, slip the front sts and reattach at the first sleeve. What I do at this point (and it's in the original pattern) is knit across the front to the marker for the sleeve, slip the marker knit across the sleeve, turn, cast on 2sts, purl back across the sleeve sts only, turn cast on 2 and then work the sleeve rows. If you knit across like this, you it saves cutting the yarn and weaving in an extra end.
When you finish the sleeve rows, you'll have to cut the yarn and reattach at the back, knit across the back to the second sleeve and work on the second sleeve sts only. When the sleeve rows are complete, cut the yarn, reattach to the next front and knit across that to the end.