use isosurface for trace of a flock???

HI

I am currently trying to iso surface the trail of a flock on ghopper. As I a new to gh I thought i would try using isoAlgae from http://digitalsubstance.wordpress.com/2012/05/09/isoalgae-symbiotic...

However I am really at a loss of what to do. i have read a lot abotu millipede and seen example but I am just confused....

Any help would be amazing

Thank you