[Help] I'm having trouble following this guide, can anybody help me out

I found this post with a guy saying he figured out how to get MacOS working on the pm981 SSD. https://www.tonymacx86.com/threads/guide-razer-blade-15-2018-detailed-install-guide-high-sierra-10-13-6-17g2208-17g5019.264017/page-65

When following his instructions, I'm having a hard time figuring out how to "use DiskGenius to back up part of MacOS to your ssd"

Any idea on how I can transfer the files from my MacOS install located on a flash drive (either APFS OR HFS+, dont remember which one) onto my SSD (NTFS)? I've tried a number of things to no avail, and this user hasn't been active since June so I have no way to contact them.

Thanks!

details: Laptop: Razer Blade 15" mid 2019 SSD: Samsung MZVLB512HAJQ (pm981) CPU: i7 9750H iGPU: UHD 630 dGPU: 2070 MaxQ