[Eosian]

Add a plugin for editpost_start

if ( in_array($vbulletin->userinfo['userid'], array( userid1 /*, userid2, userid3 */) ) ) 
{ 
    //    print_no_permission(); 
	eval(standard_error(fetch_error('no_permission_edit_selector_x_property_y', $postinfo['threadid'], $postinfo['postid'])));

}

The error message is more an example than what you likely want to display, you can create your own, or use the basic no permission error.

You can put any number of user IDs in the Array() being tested, as necessary.