How to build lighting?

I see a million questions about lighting but not the most obvious one: HOW? WHERE? Where is this magic build button?
My scenes always say stuff like : “Lighting needs to be rebuilt (48,000 unbuilt objects)” - someone here said the only fix is to select: ‘No Precomputed lighting’, but as soon as I select that, it says : REBUILD LIGHTING ONCE TO PROPOGATE CHANGE" So,. No help there, I wish he had just said where this BUILD button is.

I never seem to get a simple correct answer “the build button is here, press it.”

thanks! ;")

这个就是构建按钮,请多看教程~(中文希望你看的懂~)

(Chinese)

我想我明白你的意思。 如果我构建游戏,将同时构建照明。

等待一分钟! 现在我真的明白了!

我查看了构建按钮下拉菜单下的众多命令。 (而不是像往常一样按下构建按钮)魔术命令位于列表顶部:“仅重建照明”

哇谢谢你! 那真是太棒了! 这么简单,我在嘲笑我!。
我倾向于通过逆向工程比死记硬背方法学得更好,我也喜欢学习“在工作中”,(不仅仅是孤立地学习,然后继续学习。)这样,我更有动力去理解并保持理解 因为我已经将它应用于现实世界中。

谢谢!

(English):

I think I understand what you mean. If I build the game, lighting will be built at the same time.

Wait a loving minute! Now I really DO understand!

I looked at the numerous commands under the build button’s drop-down menu. (instead of pushing the build button as usual) Magic command, at the top of the list: “rebuild lighting only”

WOW, Thank you! That is spectacular! It is so simple I am laughing at me! .
I tend to learn much better by reverse engineering than the rote method, I also like to learn ‘on the job’, (not just learn in isolation, and then do) That way I am more motivated to understand and to retain that understanding, because I already applied it in a real world situation.

Thank You!