How to purl into back and front double yarn over

I am trying to do this lace pattern…have yet to read anything online that i can understand. So, here goes. The pattern requires that you purl into the front and back of a double yarn over. Any suggestions would be welcome…I have tried lots of different ways to no success so would welcome help.

Here’s a video that may help. It’s a little awkward but having the double yo will give you some extra ease to do the stitch.

Purl into the first loop tbl, then purl as normal into the other loop. You might have to hold a finger on the 2nd loop, or you can let the first loop drop and purl into the big loop as usual, then into the back leg.