This question doesn't really make sense---it isn't possible to accidentally pull the digitizer flex cable off the touchscreen ic that it is soldered to without significantly tearing the flex. What you are showing is a new digitizer replacement with its flex. Most iPad mini digitizers these days are solder pre-soldered to a touchscreen ic. This one is not. For this one to work, you'd need to solder the flex you are showing to the touchscreen ic chip that you are showing, and then also solder on the smaller flex connector that you are showing.
Align the gold dots with the touchscreen facing up, add flux, and solder away.
If there is any damage to the touchscreen ic, or a bend in the digitizer flex, cold or bridged solder joints, or damage to either flex at the contact pads---then the whole effort will have a poor result.
I would recommend just buying a new digitizer assembly due to the risk that something is already, or will become, damaged in the repair attempt.