Works with Baidu IME (百度输入法). Pick your phone below — Android or iPhone.
File type: .bds
Download the .bds file from your download page. If you're on a computer, send it to your phone (Telegram / WhatsApp / email to yourself all work).
Find the file in your file manager and tap it, then choose Open with → Baidu IME. The app imports it automatically.
Open Baidu IME → My Skins (我的皮肤) → tap your new theme to apply. Done!
File type: .bdi
From your download page, save the .bdi file to your device (Files app).
Tap the file → Share → send it to yourself in a chat app (WeChat, Messages…), then open the file inside that chat. Do not open it straight from the Files app.
In the chat file preview tap Open with → Baidu IME. It imports, then apply it in My Skins.