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.

[25, 266, 227, 468, 309, 322, 381, 155, 271, 86, 284, 469, 108, 499, 389, 184, 464, 384, 198, 352]
[499, 266, 227, 468, 309, 322, 381, 155, 271, 86, 284, 469, 108, 25, 389, 184, 464, 384, 198, 352]