Removing Custom Modules

Removing Custom Modules

Hello Everyone,

I'm trying to remove custom modules from my Zoho CRM. I've ran into the issue, where I'm unable to delete the Modules because there are lookup fields in the fields associated with other modules.

When I attempt to delete the modules, they are grayed out and I'm unable to remove them. 

Can I please get help on removing the modules or resetting the entire Zoho CRM to its Out of Box settings with out having to delete my account?

Thanks
SC