The most important part is that you'll be soldering to one end of the LED strip, and to make sure you are soldering to tbe INPUT end. To determine which is the input, check the writing on the flexible PCB. If it says CI DI then thats the (correct) input end. If it says CO DO then thats the (wrong) output. You can only connect to the input end so double check.
Tin the pads by carefully melting a little solder onto the pads.
The next two wires go in line to CI and DI.
The sixth wire connects to GND.