original: The northern part, the Restkreis Sankt Wendel, was merged into the district Birkenfeld, the southern part stayed in the Saarland in its reduced size.
simplifications: The northern part, the Restkreis Sankt Wendel, was merged into the district Birkenfeld.  The southern part stayed in the Saarland in its smaller size. The north of Restkreis Sankt Wendel, was added to the district Birkenfeld. The southern part stayed in the Saarland. Restkreis Sankt Wendel was merged into Birkenfeld but the southern part stayed in the Saarland. The Restkreis Sankt Wendel joined the district Birkenfeld. The southern area stayed in Saarland at a smaller size. The northern part, the Restkreis Sankt Wendel, was merged into the district Birkenfeld. The southern part stayed in the Saarland in its smaller size. The northern part, the Restkreis Sankt Wendel, was combined with the district Birkenfeld. The southern part stayed in the Saarland in its smaller size. The northern part became part of the district Birkenfeld. The southern part stayed in the Saarland. The northern part was merged into the district Birkenfeld. The southern part stayed in the Saarland in its smaller size. The Restkreis Sankt Wendel (northern area), joined into the city Birkenfeld  and the southern part stayed in the Saarland in its smaller size. The Restkreis Sankt Wendel is the northern part. It was merged into the district Birkenfeld. The southern part stayed in the Saarland in its reduced size.