grep is your very best friend.

This. And also, in many cases, an ‘adjacent’ grep may help. Say you want to move the “OK” button on one screen. Searching for the string “OK” would be overwhelming as that would be all over the shop.

But you notice there’s a “Setup…” button next to it. Searching for that could potentially cut down your search results by orders of magnitude. The more obscure the text, the better.