Please solve the programming task below using a self-contained code snippet in a markdown code block.

You are given a string s containing lowercase letters and an integer k. You need to :

First, change some characters of s to other lowercase English letters.
Then divide s into k non-empty disjoint substrings such that each substring is a palindrome.

Return the minimal number of characters that you need to change to divide the string.
 
Please complete the following python code precisely:
```python
class Solution:
    def palindromePartition(self, s: str, k: int) -> int:
```