Quality Item. Item does not include the two IC chips which you will need to transfer from the old flex connector.
Pry the chips from the old flex strip with a very fine blade via solder spots using firm pressure and wiggling the blade under the ends of the solder contacts, towards the chip.
Soldering is easy enough with magnification, re-using the original solder. No need to apply more. Be careful to check the orientation of chips cathode and anode direction as per the original configuration, using the specification figures on the chip.
Check solder connections by flexing the strip to see if chip contacts are mechanically stuck to solder pads on the flex strip.
Good luck!