Filza method

You will need jailbreak or troll store and the Chinese Brawl client installed on your device.

1. Move ktr.csv into Filza using the Share > Copy to Filza option.
2. Open Filza and navigate to the following path:
/var/containers/Bundle/applications/荒野乱斗/BrawlStars.app/res/localization
3. Delete the existing cn.csv file.
4. Paste ktr.csv into this directory.
5. Rename ktr.csv to cn.csv.

E-Sign method

1. Import the IPA to esign
2. Go to the Apps tab and press CN BS EN and tap on Signiture.
3. Go to More options and select Supports Document Browser.
4. Press Signiture and install
5. Open your file browser and move ktr.csv inside On My iPhone/Brawl Stars/updated/localization/cn.csv.
6. Rename to cn.csv

Video Tutorial here

Android Instructions (rooted only)
1. Download and install apk from [here](bs.qq.com)
2. Go to data/user/com/0/com.tencent.tmgp.supercell.brawlstars/update/localization
3. Delete the existing cn.csv file.
4. Paste ktr.csv into this directory.
5. Rename ktr.csv to cn.csv.