Seems like you have already added the CNAME record and DNS
propogation is pretty much complete. So basically you just need to
skip to the "Blogger Settings" section in that article and continue
from there.
Just a note, did you use royystonn.com or
www.royyston.com for the CNAME record? If it is
the latter, you may need to input "www." in the Blogspot settings
as well. And imo, people generally prefer URLs without that "www."
prefix.
