From memory (so I might be missing steps):
Remove the cover in the center of the valve cover (the spark plug valley).
Remove the coils from all spark plugs.
Take off the valve cover.
Zip tie the chain to each cam gear, so it can't skip a tooth.
Remove the old chain tensioner
Install the new chain tensioner
use a paint stick, and bump the back of the chain where it touches the tensioner, to activate the tensioner.
re-assemble.
You should also do the Dorman bolt fix on the side cover.
Start reading
here, and go down a few posts.
If you make the mistake I did (the chain jumped because I didn't zip tie it to the gears)
then you end up taking the engine mount off the right side of the engine and frame,
removing the pulley tensioner
removing the side chain covers
repositioning the chain on the crankshaft and both gears
then putting it all back together.