Welcome to the site !!
Hopefully you are still around , just noticed this post ...
The bike has rocker arms , so you adjust the valves by turning the engine by hand to get it on TDC and checking that the rockers are loose , you then use a 10mm wrench and a flat screwdriver to adjust the lash , you just slightly back off the nut so you can turn the screw , and with the feeler gauge in between the post and the valve stem , turn the screw till there is a slight drag , but its not stuck , then while holding the screw in place , with the gauge in still , tighten the nut , then recheck to make sure the lash did not tighten up too much , it may take you a few attempts to get it right , but when you can slide the gauge in/out without having to force it , but it not being loose , then you have it set correctly .... the lash is
(cold)
Intake: 0.003 in
(0.08 mm)
Exhaust: 0.005 in
(0.12 mm)