Feather Headers

Solder the male headers under the Feather as shown.

This guide has more info on soldering header pins onto the Feather board.

FeatherWing Headers

Solder the male headers under the FeatherWing as shown.

FeatherWing Doubler

Solder the female headers into the FeatherWing doubler as shown. 

This page has info on soldering headers into doublers.

Plug 'em In

Plug the Feather and FeatherWing into the doubler as shown.