Solder the data input to pin 6 on FLORA, all power wires to VBATT, and all ground wires to GND.
Test that all your NeoPixels work using the library's sample code! If they don't all come on, double check your pixels' data arrows and that you don't have any short circuits.
When they're all working, it's time to sew them in place! Use clear or color-coordinating thread to stitch just before and just after each pixel, knotting off at each one for the most durable construction.