How to? (lawn)?

Question:i have a Poulan PL 25 weed wacker. i bought a weed thrasher that said it would work on Poulan brand but there are no nuts that will fit into the bolt of my weed eater. how can i do it or is there a speacial trick to doing it or do i have to return it.?. or is there another nut that could possibly fit it? one that i may purchase or sumthing?

Answers:
its made for bigger machines. sorry to tell you but you may have to return it