So Dorf has given us his professional, degree backed, information on how to use, not assemble, a brush-cutter, which involves removing its safety features.
Can we assume the commercial use of brush-cutters is generally, labourers, who are instructed on safety by those with their knowledge, you, a degree holder....
I must say, this all sounds like a disaster waiting to happen, instigated by someone, with a degree, that should know better......
To post this non-safety stuff on a forum, with maybe beginner, not in the know gardener, seems rather reckless, though expected, from you......🥴