Remove Secdroid and go back to android

Hello,
I have an ancient smartphone using secdroid, since it has replaced by a new one, my entreprise gave it to me.
As I can’t use it as I would, I’d like to remove Secdroid and reinstall Android.
Can anybody explain me how can I do this ?

Thanks.

which device? Can you reflash as normal? Eg. Find yours on https://forum.xda-developers.com/

Thanks for your answer
The device is a Sony Xperia X and sadly I can’t reflash as normal

Are you sure? I see there is development for the device.

Sony Xperia X | XDA Forums