General synonyms:
* Exchanged
* Traded
* Bartered
* Replaced
* Interchanged
* Substituted
* Switched
* Changed
More specific synonyms:
* Shuffled (if the order of items was changed)
* Flipped (if two items were switched places)
* Transposed (if two items were moved to different positions)
* Conversed (if information or ideas were exchanged)
Informal synonyms:
* Ditched (if something was replaced with something else)
* Made a deal (if two parties exchanged items)
* Got rid of (if something was replaced)
The best synonym to use will depend on the specific situation and the meaning you want to convey.