Connect to your instance of MS SQL Server where you want to deploy the T-SQL Toolbox. Connect with a user having sysadmin rights. Just run the T-SQL script which is provided for download.
To use it in your environment just grant the access permissions for the whole TSqlToolbox database or dedicated database objects according to your specific requirements.
And your are done! Enjoy it!
CAUTION: Update is done using DROP/CREATE database! So, adding any personal stuff in the TSqlToolbox database is NOT supported!
The documentation for usage can be found within the comment header of each database object. There you can find a detailed description as well as some useful samples.