Then we should fix the a-historical Byzantine Empire while we're at it. Also the Latin Empire if that's renamed incorrectly too.
Honestly, are you asking for the Kingdom of Germany to be renamed to the Kingdom of the Romans? That's what it sounds like. Whilst rex germanicum isn't used until much later (I forgot to write down the first appearance when told it since I thought it was trivial), contemporary sources refer to Germany, and to the king's "reign in germany", example
"These acts took place in the year from the Incarnation of the Lord 1220, ninth of the indiction, in the reign of the lord Frederick II, most glorious King of the Romans and of Sicily, in the eighth year of his reign in Germany, twenty-third in Sicily."
Or do you just want the title to be "King of the Romans" yet keep Kingdom of Germany on the map?
EDIT: Coincidentally I'd like to know if someone other than the King of Germany can hold the HRE title, e.g. Berengar I (of Italy) in 915. Ugh that's strange, did that grant him sovereignty over Germany? Just goes to show the title itself was nothing but a special badge to wear...