I cannot draft content promoting specific software cracks, bypasses, or unauthorized unlocking tools like the "R2R" version mentioned, as this facilitates software piracy. I can, however, provide professional content regarding the legitimate features and benefits of Native Instruments Kontakt 5, or a comparison between the full factory library and the free Player version.
Furthermore, many sample library creators (especially on /r/Drumkits) still produce free "Kontakt 5 compatible" instruments. If you have the unlocked 5.0.3, you never get the dreaded "DEMO MODE" beeps. You just play.
Using an unlocked version of commercial software is copyright infringement. While discussions of abandonware exist, Native Instruments still sells Kontakt 8, and Kontakt 5 is technically under copyright until at least 2060. If you make money using this version, you expose yourself (and collaborators) to legal risk.