Enter your email and password and click "Sign in". This is in the upper right corner and will bring up a dropdown menu. You will be taken to the Dropbox settings page with the "Profile" tab displaying by default. Window will appear where you can drag/drop a photo to upload it or click to browse your computer for image files. This button is located to the right of your name displayed on your profile. A window will appear where you can enter a new first and last name. This link is below your current email displayed on the profile. A window will appear with a field to enter a new email address, and 2 other fields to verify your current login information. Click "Change" next to "Language" under the "Preferences" header to bring up a window with various language options. This setting will be made for Dropbox across devices. Select the checkboxes under the "Email Notifications" header to choose which actions notify you via the email associated with your Dropbox account. This button is located near the top of the page and will take you to the Account settings. Click the "Connect" button next to the associated service link your information to that service for updates and notifications. You can link social media (Facebook, Twitter), email (Google, Yahoo), or personal contacts. Click "Delete My Dropbox" near the bottom of this page to permanently remove your account. This button is near the top of the page and will take you to the security settings page. Here you can view recent login sessions on your account from various devices. This button is under the "Password" header and will bring up a window prompting you for your old and new password. Click "Change Password" to confirm the change. Click "Click to enable" next to the status under the "Two-step verification" header. You will need to supply a mobile phone number that will become linked to your Dropbox account. You will be prompted to enter a code texted to that mobile number each time you sign in to your account from an unrecognized device. Click the "x" to the right of the device or app listing under the "Devices" or "Apps Linked" headers. This will remove its association from your Dropbox account and stop any syncing with that device or app.

Summary:
Navigate to https://www.dropbox.com/login in your web browser. Sign in to your account. Click your account name. Click "Settings". Click your account photo to add or edit the photo. Click "Change" to change the name on the account. Click "Change Email". Change language settings. Change email preferences. Click the "Account" tab. Link other accounts to your Dropbox. Delete your account. Click the "Security" tab. Click "Change Password". Enable two-step verification. Unlink devices or apps.