I couldn't find the sweater that you're doing but I have a question and a suggestion.
Is this the entire row "...Patt 3, patt 2 tog, 5 times, patt 3.." with all the parenthesis etc? As is, it's not enough to account for 58sts or for 6 decreases. It could be a pattern error.
If it's the row after the rib and before the main pattern for the body, you could just decrease 6sts approximately evenly spaced across the row. Work in rib pattern and k2tog or purl2tog at the decreases.
For example: rib 8, work 2sts tog, rib 6, work 2tog, rib 6, work2tog, rib 6, work2tog, rib 6, work 2tog, rib 6, work 2tog, rib 8.