Oh God almightly, BE CAREFUL!!! I did this. There is a drawing in the manual for a wood wedge that is used to block the chain tensioner from moving when you create slack. The drawing is deceptive - that tensioner is much farther down inside the timing gear cover than you think it is. I have been in there, and I personally would NOT do that unless I could get a very accurate wedge drawing from someone with a demonstrated working wedge. (I'm delighted that you have a volunteer for this.)
That wedge has to be way down in the timing cover, and it must be tapped into place VERY firmly. I thought this was a rather trivial deal when I pulled the cam sprocket, but it is NOT. It's a potential huge pain in the arse.
Screw that up, and you'll have to pull the fan, water pump, crank pulley, and timing cover to get at the tensioner. It is VERY difficult to get that timing cover back on with the gaskets oriented properly with the head on the engine. I gave up and had a professional shop do it.