advice needed for removing hydraulic tappets on v6

[hogggman]

hi all,
It`s time i further inspected my tappet/camshaft noise on my v6.after 2 oil changes and various additives,it is quieter but still sounds like a diesel.i now have to inspect further to ascertain whether i do in fact have one or more stuck hydraulic tappet,or if i have camshaft damage.i do not have a manual at present,so will initially remove the rocker covers to have a look.will camshaft damage be obvious?hopefully i may be able to check if any hydraulic lifters are stuck by turning the engine over and trying to manipulate each one.ideally then i will remove them all,and thoroughly clean/dismantle/oil/replace them to see if this helps.will i have to completely remove camshaft,cambelt etc,to do this,and will i be able to simply mark the position of everything for easy reassembly?i don`t suppose anyone will know any torque settings for any bolts that i may need to remove?
one thing i thought of,is that i may be able to get a `pattern`hydraulic lifter if i need to replace any.if i get some the same shape/type/diameter,will these be ok?do they have to have an exact amount pof `lift`or`play`?
thankyou
jamie

[dandywarhol]

Google Image search "worn camshaft" and you'll see what I hope you don't find...............