I wasn't actually meaning the ten commandments in that context no. The change to the priesthood with regarding law is related to the law of Moses... Those laws associated with the services of the sanctuary. As explained in Hebrews, Jesus was not born of the tribe of Levi, therefore by law could not be a priest, therefore it necessitated a change in that law regarding priesthood.
KJV Hebrews 7
A New Priesthood Warrants a New Law
11 If therefore perfection were by the Levitical priesthood, (for under it the people received the law,) what further need was there that another priest should rise after the order of Melchisedec, and not be called after the order of Aaron?
12 For the priesthood being changed, there is made of necessity a change also of the law.
13 For he of whom these things are spoken pertaineth to another tribe, of which no man gave attendance at the altar.
14 For it is evident that our Lord sprang out of Juda; of which tribe Moses spake nothing concerning priesthood.
Read further in Hebrews 8 for the fuller picture.
The priesthood, are you referring to the Kingdom message? If possible you will need to look at it closer and determine if the born again fits that or not. My understanding is; that was for Israel! the born again and Israel are two separate entities. Never a people like the birthed of God before, hence they would have to have a message that fits who they are. We are not kingdom people persay (the kingdom is within) but bonified offspring of God. That does not fit any other people's or message's in scripture, division must come into play at some point in a believer's life and knowledge of scripture.