How does one reuse a thick film circuit?
Those are carbon traces, so can't be soldered to.

Note the fingers at center top.  Those are meant to go into a connector that will mechanically clamp the conductive part against metal contacts in the connector.  They could also be meant for a "zebra stripe" connector, or something that is screwed down on the PCB that holds the carbon against pads on the PCB for that purpose.