Select the stands you would like to rotate.

If you want to rotate the stands against an angled venue wall, move them into an approximate position as shown below. You can move them more finely again after rotating.

With the stands selected, click the Rotate button which is located on the MODIFY menu as shown below.

You now need to select a pivot point for where the stands will rotate around, in this case I will select the top left corner of the block as highlighted with a Blue circle below.

Now select another, different point to use to drag the stands around the pivot point. This point can be anywhere but in the example below I have selected the opposite corner of the block as highlighted with the Blue circle.

Now just move your mouse around the pivot point until you have achived the angle you require, then click your mouse.

You can see the angle you have rotated the stands by the indicator as shown below highlighted in Red.