如何减少构建中的组件数量？

I use an ESP8266 module with 1Mbyte flash, I would like for my project to ass FOTA feature, in this case I have approx 450ko for each binary app. When I use the sample code "native_ota1MB_flashnew_to_new_no_old" the binary have 440ko flash size then work on my my module. But I just Add smatConfig and MQTT (very simple code for now) but the size go to 456ko. Then this binary is too large to enter in my module.
由于我的应用程序不需要某些组件，因此我想知道如何减少我的项目中链接的组件数量。