I suggest neither melting nor crimping because the copper is way to thin and fragile (unlike magnet wire, where you melt away the insulation - and unlike a comparatively massive stranded or solid wire used for crimping, the 17, 35 or 70 µm Cu layer on flex "boards" is just way too thin for either method!).
Flex boards are usually composed of a polyimide (PI) substrate below and a coverlayer above the etched copper traces:
xxxxxxxxxxxx coverlayer or flexible soldermask
------------ Cu traces (thin!)
============ PI substrate
PI is heat resistant and as a base material for copper traces to be soldered on, is about as good as good ol' FR4.
Try finding out on which side you have the coverlayer, use something sharp to scratch it off, and try to solder onto the copper that remains on the PI substrate. The best way would be to clean away the coverlayer (or flex soldermask) and put the thing into a ZIF socket, because solder blobs on a flex "board" might not last long under mechanical stress - but I guess for a hobbyist's approach, soldering might do.