Replacing a cam is not very hard.

1. Remove the rockers.
2. Turn the engine to align the marks on the cam (or gear)
3. Remove the small cover in front of the cam.
4. Loosen the bold holding the gear.
5. Remove the chain tensioner (put it in a plastic bag, otherwise you can lose parts).
6. Remove the bold holding the gear.
7. Slide the cam to the back and remove the gear.
8. If you have enough room in front of the engine you can now slide the cam out, otherwise you have to remove the cam tower.

The tensioner is spring loaded, you have to slide the inner part out and reinstall if from the back. It is a bit tricky, I put it in a plastic bag when working on it.