its still possible, all you do is open up 2 windows on the detail screen, selct them both low detail (as u cant do 2 high detailed ones). This make both screens small so that you can click login on both easily. Then type in the username and password for both accounts but dont click login
The next part is slighly harder as u need to be quick at pressing login on both. It'll take some practice. If u fail u have to redo the whole process again