How to disable rooms module?

How to disable rooms module?

I am getting a grayed out checkbox and a:
"Required by: Drupal (Field type(s) in use - see Field list),"
Additionally, the "Booking and Availability Tools API" indicates it requires "rooms" module but also required(!) by "rooms" module...This makes no sense...?

I have installed the rooms module and all dependencies.
Disabled modules in order of dependency,
Uninstalled modules after every disabling step,
Run cron after each uninstalled module...

It looks like the disabling / uninstalling procedure does not delete field name
rooms_booking_unit_options
created by the rooms module installation itself...

Performed:
To disable a module via phpMyAdmin you must login to phpMyAdmin. Then you must locate the database where Drupal is installed. Once you have done so look for the "system" table. Click and open it. Click to browse the table. Find the record for the module that is causing the problems and select the edit function. Set the status to "0" and save.
This procedure disabled the module rooms but selecting "flush all caches" crashed the site... So I set that parameter back to 1.

Any ideas for a beginner? Anyone?
Michael.