Secure the PowerBoost to the pair of helping third hands. Apply solder to the following pins: Positive(+) out, Negative(–) out, EN, GND, G and 5V.
Measure Wires for PowerBoost and Amp
We'll need about 3cm in length of 30AWG wire to connect the Amp to the PowerBoost 1000C. Use wire strippers to remove about 4mm of insulation from each tip and apply solder to tin them. Now secure the amp to the helping third hands and solder the wires to the Vin and Gnd pins.
Connect Amp to PowerBoost 1000C
Slip on a piece of heat shrink tubing to the wires connected to the Vin and Gnd pins. Next, secure the PowerBoost 1000C to the helping third hands. Solder the VIN wire from the amp to the 5V pin on the PowerBoost. Then, solder the Gnd wire from the amp to the G pin on the PowerBoost 1000C.
Now our amplifier and speaker are wired up the PowerBoost 1000C.
Test fit Power Switch
Next up we need to connect our slide switch to the PowerBoost 1000C. First, we should do a test fit and see if our switch can fit into the case. Insert the switch into the switch cutout of the bottom case. Press it all the way through. If it's too tight, you can use a filing tool to open it up.
Prep Slide Switch
Remove one of the legs from the slide switch. Secure the switch to the helping third hands and apply solder to the two remaining legs. Now we'll need two new 30AWG wires that measure abot 7cm in length. Strip and tin the tips of each wire.
Connect Wires to Switch
Solder the two wires to the two leads of the slide switch. Add pieces of heat shrink tubing to each terminal to insulate them.
Connect Switch to PowerBoost 1000C
Now we need to solder the two wires to the EN and GND pins of the PowerBoost. The polarity doesn't matter that much here. The switch can be installed in your prefered position later (ie. Up position is ON, Down position if OFF, it's up too you!).