pretty easy turn the wheels to the right so you can see the timing mark on the balancer.
next lift the car and remove the plastics so you can get at the balacer think the bolt is like a 24mm or something
next remove the valve cover
remove the timing chain tensioner
zip tie the cam sprockets to the chain and remove the sprocket
remove all the retainer bolts for the cams, notice some bolts have groves cut down them for oiling, they need to be put in the same positions
install new cams and torque everything down. not sure about torque specs but its like 14 on retainer and like 40 for the sprockets
install the tensioner outer portion first then the inner.
turn the engine over by hand a few times... very important.
line up timing marks and make sure everything is lined up.
reinstall valve cover and undertrays
run the engine make sure it runs good and then change the oil. all the crap you think didn't fall in prob did so change it.
anything i missed let me know i did this like 6 months ago, going off my memory
99 lb viggen