Don't drive it at all till it is fixed! Those are VERY delicate engines.

It is not too hard but plan on all day the first time you do it. I like to zip tie the timing chain to the gears before removeing them so I a positive they go back exactly where they came from. You can do them with out pulling the radiator and core suport but they are easy to remove and make the job much easier. Also make sure you have a good 3 jaw puller before you start and it has to be kind of small to get in there. Take your time and make sure you get it sealed properly. I replace the tensioner as standard procedure now