In this task, you are given a list of unique integers you need to swap the positions of maximum and minimum element in the list and return the updated list.

[263, 243, 453, 429, 188, 419, 308, 14, 28, 298, 301, 140, 229, 203, 125, 136, 199, 270, 439, 279]
[263, 243, 14, 429, 188, 419, 308, 453, 28, 298, 301, 140, 229, 203, 125, 136, 199, 270, 439, 279]