By reset, what do you mean? If you mean revert to CEX, then you need to convert to CEX mode using Rebug Toolbox and then install a CEX CFW over 4.81 D-REX. However, I'm not sure what exactly you mean by reset.
By reset, what do you mean? If you mean revert to CEX, then you need to convert to CEX mode using Rebug Toolbox and then install a CEX CFW over 4.81 D-REX. However, I'm not sure what exactly you mean by reset.
In that case, all you need to do is reinstall the 4.81 D-REX PUP (or a higher version such as 4.84.2 D-REX) via System Update > Update via Storage Media. Any custom coldboots, boot up sounds or XMB modifications will be reset when reinstalling the firmware, just so you know.