Sorry I was a bit slow to answer, didn't spot your message.
I wrote a longer message of what I do when adjusting the valves, but I had to cut half of it away ! - you can only post 1000 characters as a message...
All the best with the valves
I couldn't find a tutorial when I first did the valves, read Haynes manual and manual from this board.
Measure gap between finger follower and shim on top of valve - often other shims can be used from other valves, if you measure all the clearances first.
There's a knack to lifting the individual follower and sliding it over to one side - I use a blunt screwdriver to lever the follower 'up and over'. Remove the shim with small magnet. The spring loaded cam followers can be easily moved back over.
It's not too difficult and with luck most valves won't need altering. I measure the thickness of the shim too, I know they're marked with the thickness, but they can wear a touch - nothing worse than working out what new shim you need, fitting it, measuring all the clearances again and find one's out !
It pays to have pen and paper, list each valve eg ex. 1 to 8 and in. 1 to 8 to record what you've done, once they've been set they don't move too much.