how to convert Kimi-K2.5 base model is in INT4 format to BF16 before SFT

### Reminder

- [x] I have read the above rules and searched the existing issues.

### System Info

Hello, I wan to sft or lora K2.5, In https://github.com/kvcache-ai/ktransformers/blob/main/doc/en/SFT_Installation_Guide_KimiK2.5.md, it says:
```
1.2 Convert INT4 → BF16
Kimi-K2.5 base model is in INT4 format, convert it to BF16 before SFT.
```
But how to convert from INT4 to BF16, any scripts?

### Reproduction

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### Others

_No response_