Unable to use or remove OCLP due to Bootcamp?

I followed a MrMacintosh Video, installed OCLP and did "Build and Install Open Core" on my local hard drive. I use a late 2015 iMac with Monterey 12.7.3 that also has a Windows partition installed with Bootcamp. After rebooting my system and entering the booting mode, it had the option to boot iOS as usual and the Windows option but with the new OCLP symbol, but no option to boot iOS with OCLP. I picked Windows with OCLP which performed some update but worked as usual.

Now, I'd either like to actually run iOS with OCLP to enable AirPlay or remove OCLP again altogether. I thankful for any tips or points to useful resources. I should point out that I'm an absolute beginner to this. For example, I found this guide to uninstall the Bootloader but I'm totally overwhelmed by it. How do I even mount the EFI partition? Also, I can't find the described EFI folder in the boot folder or anywhere else.