...select the picture with the right white balance in LR, you can then at the bottom of the screen, press the shift key and select all the picture you want the change to be applied. Then on the lower right of the screen press the sync button. A pop-up screen will appear asking you which feature you want to apply to all your picture. Simply select the white balance and then clic synchronize again.
This is the fastest way.
Sorry forgot to mention you need to be in the Develop mode in LR for this to work.
Wow...is it just me, or does:select all the relevant images, click on the WB eyedropper tool, click on the gray card in one of the images, and done
...sound a whole lot easier? I really hope there's an easier way to do it in LR, else from a workflow standpoint alone I'm glad I use DxO!
Yeah - you literally copy and paste.
command/control C - select white balance
then paste it onto the relevant images with command/control V.
Doesn't get easier than that.