How do you find helpers for larger DIY projects?
Many community colleges offer construction trade courses. Have a chat with the instructor, he can often offer enthusiastic young students who are ready and willing to provide some sweat as an on-the-job learning opportunity.

The students get class credit, the only cost to you is to buy them lunch and provide water, no insurance/license, etc. required because they are covered by the institution.

This is assuming the instructor finds your project suitable and the work area safe.