Using 2 balls of yar

Hi, I’m knitting a cowl neck poncho and have come to a bit that says use a separate ball of yarn and cast on 76 stitches, leaving these on a spare needle. Then it says purl my original 26 stitches, then purl the 76 stitches on spare needle - 102 stitches. Does this mean you join both rows together and if so how do you do it with the 2 separate balls of yarn?
Thanking you in advance.

What is the name of the pattern? If you have a link please provide it, but don’t post the pattern itself here due to copyright issues.

Hi, it’s woman’s weekly The Big Easy. Don’t have a link. Thanks

Found it!