How to Uninstall Comodo Mobile Security

I have a cell phone BQ Aquaris 3.5 with android 4.2.2 and i need to make a firmware update, but I can’t becouse it enters in a cycle demanding to install. I think is about CMS running. I tried to unistall CMS, starting to disable administrator rights on the phone, but I’m not getting because the selection doesn’t come out.

I have CMS 2.5 with virus definition 40.104

I selected Device Administrator, unchecked Comodo, and get the option to cancel or deactivate. Selecting deactivate does allow me to uninstall, but note, as long as it is on the phone, it will always be displayed under Device Administrator, just not activated/checked.

My phone :
Samsung Galaxy S5 SM-G900W8.

Hello John,
Thanks for your reply.

Well, I selected Device Adimistrator and unchecked Comodo, and choose deactivate (but the box remained enabled). Then, I go Settings > Apps and choose Comodo, but the buttons “Force stop” and “Uninstall” are grayed and I cannot complete the uninstall.

I appreciate your help.