Help! Decreasing in half fisherman's rib

[MooseBeTimeForSpring]

Please help. I've returned to knitting after many years (give or take the odd pair of socks) and I'm knitting a baby jacket as a gift for a friend. I'm working on the right front piece and I need to decrease 1 stitch at the start of alternate rows to shape it. The pattern is p1 k1 p1, k1b p1 repeat to end

The pattern doesn't tell me how to decrease the stitch. Where the hell (and how) do I do it without buggering the rib up?

Your help is very much appreciated. Google is driving me nuts. I'd like to finish whilst there's still a chance the jacket will fit.

I am assuming the bit in bold is the pattern that you repeat until the end of the row. Then if the p1, k1, p1 bit is a (moss stitch?) band at the centre edge of the garment then I would be inclined to increase after working these stitches.

Just k2tog and then work the appropriate pattern stitches afterwards. Work the second row as normal in pattern to the end.