Members who already have a Yuku / Lefora / Forumer account can be invited via the community's invite page. Once invited, you can adjust their forum access settings before they start to post.
All admin actions, including member invites, require that you are signed in with an account that has admin access to the community you wish to manage.
The admin dashboard of your community can be accessed by clicking the "admin" link in the community's navigation bar.
To get started, click the manage link in the sidebar on your dashboard
Next, click Invited in the member menu:
Type a username in the box and click the Invite button.
It is very important to include the extension when you invite a user, without the extension, the invitation will not go through.
Extension is the part between the actual username and .yuku.com. Example: Chrisw.u.yuku.com : .u is the extension and you would invite this users as chrisw.u chris-w962.chriswsplace.yuku.com : chriswsplace is the extension and you would invite this user as Chris W962.chriswsplace
You can check a list of your invited members by clicking Invited in the admin menu, or you can filter your invited members via the status drop down in the member filter.
The invited profile will receive a private message, inviting them to join your board. They will not be a real member of your board until they accept your invitation (by posting). Making a first post is what will change the invited status to member status.
Before they join, you can adjust their forum access settings on their individual member management page.