Greetings Wanda:
I wouldn't cut off the leader of this pin oak just because it is growing crooked. Rather, the leader needs to be trained -- assuming it can be trained.
Often times with young black walnut trees, we will splint a terminal leader to "force" it vertical (i.e., take a wooden splint and affix the wandering leader to it using masking tape). The splint extends down the main bole so as to provide structural integrity. Alternatively, you can tape the crooked terminal leader to an adjacent branch, thus forcing it to grow in a vertical position.
Best of luck!