How to assign multiple people to a project.

How to assign multiple people to a project.

Hello,

I have 140 people in my organization. I have created a generic project for Project Management and want all people to be part of it as it will contain tasks like presales, training, support etc. How can i assign multiple people in shortest time. I cant add people 1-by-1 as it will take too much of time.

Regards
Vishal