transfer from internal licenser to e-licenser

I have Elements 2 (or might be 3) running on my Surface, Dorico Pro 3 running on my Macs. I have now purchased an e-licenser, so can run Dorico Pro with the e-licenser on my Surface. I do not think there is a “de-activation”, all the references I have read here relate to doing the change on your computer or using another, then clicking on the red Activation button at the Steinberg website to re-enable it.
So do I simply just plug in the e-licenser and Dorico Pro will start, or do I have to do something in the e-licenser software on my Surface to have it point to the dongle… then what do I do with Elements license if I cannot deactivate? Does it just hang somewhere for a future time when I can do the red activation button on whatever computer I want it to run on (at this point, I will probably not need to use it just now.) I do not want to lose the Elements license in case I need it in the future.

Thank you.

At the point of purchase, the dongle is empty. You have to move a Dorico software license from a computer onto the dongle. Once you’ve done that, it’s just a case of plugging the dongle into whichever computer.
My suggestion would be that you leave the Elements licence on your Surface; it’ll be ignored when the dongle is plugged in but respected when the dongle is elsewhere.