Hi Mark,
As there is currently no supported procedure to remove the content packs in one go, you can do the following:
1. Get the Addin's guide with the complete list of included features.
2. Connect to Clarity PPM UI - Go to:
Lookups
Queries
Portlets
Objects
3. Select and delete all the content you don't think you will need, based on the manual from step 1.
This is going to be safe for your environment.
Please note that you may want to delete the portlets first, before the queries, as otherwise it may throw a warning.
Another thing for you to note : PMO Accelerator is used on Clarity PPM 14.2 and higher for Reporting and OOTB reports. If you choose not to install/upgrade it, the reporting functionality in version 14 will be impacted.
Please let me know for any questions.
Kind Regards -Nika