Increasing with a separate ball of yarn?

So the pattern has called for me to break off my yarn previous and re-attach the main ball. Then it told me to turn the work and go back to where I had broken off the yarn. It then tells me to P4 with the smaller ball of yarn (where I had broken it off) - I am assuming these are increases but how do I do it?

K2, (leg opening is here), break yarn leaving a LONG tail (you will be using this to knit the stitches between the leg openings – approx 4 -5 feet should be fine), rejoin main ball to the next stitch and K32, turn (you will be at next leg opening), P32, P4 between leg openings (using little ball), turn, K4, K32 (using main ball), turn, P32, P4 (using little ball), K2 (you will be at beginning of round).
You have worked both sections simultaneously and made your leg openings. Now you will be closing the leg openings up

You won’t be increasing just using the small ball of yarn to work the 4 sts between leg openings. Just take it step by step and it should work out fine.

but where are these 4 stitches that i am purling? previously it had said to cast-off 4 stitches, are these the 4 stitches i am meant to be purling?

To make leg openings:
Next round: K2, CO4, knit to last 6 sts, CO4, K2.
K2, (leg opening is here), break yarn leaving a LONG tail (you will be using this to knit the stitches between the leg openings – approx 4 -5 feet should be fine), rejoin main ball to the next stitch and K32, turn (you will be at next leg opening), P32, P4 between leg openings (using little ball), turn, K4, K32 (using main ball), turn, P32, P4 (using little ball), K2 (you will be at beginning of round).
You have worked both sections simultaneously and made your leg openings. Now you will be closing the leg openings up

Oh, see the CO 4? That’s where you get the 4 sts. You cast on using the knit or cable co and there they are.