Interior blower from Opel Vivario (B) no longer works

Hello! With my Opel Vivario the fan for the interior has failed. The fan does not turn on in any position ( 1 – 4 ) any more. I have already checked the fuses. Therefore now here my question: Does anyone have experience with the expansion of the fan or the resistance ? How high is the effort ? The spare parts are affordable, but according to the workshop the complete amature board must be removed in order to be able to change it … can be ned – or?