To export a report from the Report Builder, first ensure that all your criteria and columns have been set and you have select Run report.
Once the report has run, select Export to CSV from the top of the screen
Depending on the content of the reports (i.e. Events, Audits, Compliance etc), you may be given the option to redact the data before exporting.
Select your redaction type and click Export.
The report will then download and can be opened in Excel should you wish to manipulate the data further.