Installing ROCK on NUC6i3SYH with existing libreELEC OS

I’m thinking of running my Roon Core on a NUC6i3SYK to replace my existing Windows 10 HP Envy i7 laptop. I used the laptop to try out Roon after it became surplus when I moved to a iPad Pro 10.5 (the iPad Is used as my Roon remote), now I like Roon so want to use a dedicated Roon core.

My question is this, the NUC I’m looking at buying has a LibraELEC OS installed. Does installing the ROCK software automatically overwrite the existing OS or does it have to be uninstalled first and if so, how is this done?

Am pretty much a newbie and approaching this ROCK diy exercise with trepidation, forced upon me by my inability to justify the expense of a Nucleus. Hope someone can point me in the right direction.

Configuration as follows:

NUC6i3SYK
Intel Nuc Skylake i3-6100U
2 Core 4 Thread
2.30 GHz

2x 4GB DDR4
Kingstone 128 GB m.2 SSD
1 free 2.5" SATA HDD slot

Intel HD graphics 520

Intel Dual Band Wireless-AC 8260 and Bluetooth 4.1
Consumer Infrared sensor on the front panel

LibreELEC pre-installed

It will overwrite any other OS.
https://kb.roonlabs.com/ROCK_Install_Guide

Thanks for the quick reply, much appreciated.