850 the conversion to Volvo level of springs tensioning

Have a cheap offer (complete set levelling set Volvo part number: 9124841) and a question regarding conversion. Do you need a special tool for the removal of the old springs or for the installation of the longer thinner springs? How are the experiences? Is it possible with other means? Would I be happy to be a skilled hobbyist (but not a specialist) with tips. Grazie