Step One: To log into your account, go to The Sandbox website (click here). Then click the blue sign in button in the top-right of the page, if the login prompt doesn't appear right away.
Step Two: Log into your account using one of the provided options:
(A) Click the corresponding wallet option, depending on which wallet you connected when you registered. Then sign the login confirmation when your wallet pops up. (If your wallet does not pop up, try disabling all ad-blockers and pop-up blockers temporarily).
(B) Alternatively, click the "I already have an account" option to log in to your account using an email and password.
To log out of your account at The Sandbox, go to your profile by clicking "Me" on the bottom left of the website (or by clicking here).
Now click the three dots that are in the top corner of your display picture. And select the Log Out option.