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

You are given an integer array nums and an integer k.
For each index i where 0 <= i < nums.length, change nums[i] to be either nums[i] + k or nums[i] - k.
The score of nums is the difference between the maximum and minimum elements in nums.
Return the minimum score of nums after changing the values at each index.
 
Please complete the following python code precisely:
```python
class Solution:
    def smallestRangeII(self, nums: List[int], k: int) -> int:
```