Using the Swiss Bar for overhead presses is an excellent way to improve the strength of your shoulders and triceps if you want to avoid placing undue stress on your busted up shoulders. If you have rotator cuff issues, elbow pain, or any other sort of shoulder pain, using the Swiss Bar could be the answer to your problems.
To perform the lift, place the Swiss Bar in the rack slightly above shoulder level. Use whatever sets of grips you'd like, but keep in mind that the closer your grip is, the more stress you'll place on the triceps. Then, just press the bar overhead and lock it out hard at the top without snapping your elbows. Locking it out without snapping your elbows helps prevent stressing the elbow joint. Feel free to use as strict/loose of form as you want (we aren't going to police you), but make sure that you don't end up doing a push press when you should be doing the much stricter overhead press.