Align the direction of the goose-neck (adjustable quill stem) with the front tire.

Firmly tighten the goose-neck (adjustable quill stem) bolt using a 6 mm Allen wrench.

Pop the bolt cover back on.

If calling a bicycle repair shop, refer to it as a adjustable quill stem (technical term) instead of goose-neck as mechanic may not know what you are talking about.