Schneider was made a Generaloberst of the SS in 1937. In 1941, he was appointed to lead the forces participating in Operation Leiningen (the invasion of Brunant), alongside Josef von Helwer. The operation was conceived by Hitler, Schneider and von Helwer.
After capturing the country, he was appointed military commander and harshly oppressed any resistance. Schneider was known for his brutal tactics against the resistance and he is known to have personally killed 13 members. When the U.S. Army liberated Brunant in July of 1944, Schneider tried to flee Koningstad, but was captured by the Underground Revolution outside the capital. Fearing a rescue operation by SS units, they tied him to a tree and shot him, leaving his corpse for others to see.
Schneider's first wife died shortly before the war from cancer. He had an affair with a Brunanter, Louise Hirschfield, with whom he had a daughter, Linda. Louise committed suicide 3 days after Schneider's capture, in order to prevent being captured by U.S. troops or resistance fighters. Linda had married Alexander von Jungsburg, the Chief Justice. Later, Alexander was shot dead.