Ah! ok. That is a whole different process. Firstly, you will have to create a node on the curve in line with the D30/31, that will be your swivel point. You can use the Intersect Curve and Line tool to do this.
And you will need to make a node at the bottom (wrist edge) where you would like to open up to widen the wrist edge and join it with a line to establish the current angle. It will also help to create a node to the left and right of these added nodes the distance that you would like to open up (this can be edited to be bigger or smaller later, if you wish). Then join the 2 sets of nodes with a line each to use for the angles that you wish to widen the sleeve.
Then using the Rotate tool, you will select all the nodes and curves that you want to rotate except the new one on the curve edge, press Enter, select the new node on the curve edge and move the select a little and press Enter.
Open the Options (as before) and add a formula that deducts the one new line from the other to move the selection to cover the outer line created.
Repeat on the other side.
You may want to redraw the sleeve cap curve and also create a curve at the wrist edge that passes through all the nodes created.
If you don’t manage, let me know and I will do some pictures of the process tomorrow.