Soaker help

I’m making (or attempting to!) a CP soaker, and I’ve got to the part where I do the crotch part, and I’m confused. How do I do this on circulars, with the other stitches (from the back I believe) still on the needle? After I’ve BO 5, then knitted, then BO the other 5, then I turn it and purl-- how is this done on circs with other stitches on it? I’m probably making this way more difficult then it really is… but I’m seriously confused! Thanks for the help.

“[I]Knit from start of round to first marker (right hip). BO 5
stitches. Knit to 5 stitches before hip marker (left hip), BO
5 stitches.
Knit across, k2tog last 2 stitches. Turn and purl (or knit
backwards) until 2 stitches remain. SSP remaining 2
stitches. Repeat these two rows until 18 [18, 20, 20, 20]
stitches remain (4.25-4.5 inches). Leave stitches live on
needle, snip the yarn, and return to stitches between the
BO sections (front of soaker[/I]).”

You turn the needle around just as if it’s a straight one and purl with the WS facing you.

Okay, one more silly question. When bidding off, when I get to the “knit to 5 stitches before the next hip marker and bind 5 off” do I use the 6th stitch before the marker to start binding off, or knit the first of the five, then the second, then slip the first over the second? Thanks so much for you help.