Delegator
ORCID allows you to add an individual as a delegate. A delegate is somebody who you give permission to update parts of your ORCID record for you. The most common task you may want to ask a delegate to help you with is to update your publications. Beyond that, a delegate can add / edit information under Employment, Education, Distinctions, Memberships, Funding and Works. A delegate can *not* add Trusted Organizations or Trusted Individuals to another persons ORCID record.
To add a person as a delegate, login to your ORCID account. On the right-hand side of the screen use the drop down arrow beside your name and select Account Settings. Scroll down past Account Settings and Trusted Organizations to Trusted Individuals. A trusted individual must have an ORCID account. Add the person's email address associated with their ORCID record or their ORCID ID to the box. Then search for and give delegate access to the person you've chosen to be a delegate on your ORCID record.
More information about adding Trusted Individuals is available on this help page - https://support.orcid.org/hc/en-us/articles/360006973613-Add-a-trusted-individual-to-your-account
Delegate
Once somebody has added you as a delegate you can find access to their account via your ORCID page. Login to your ORCID record. On the left side of the page under your name find Switch Account. Click this button and select the delegate account you need. In that same place, Switch Account, you can move back to your ORCID record when you're done.