How does one do this? I have removed the front seat etc, but I still can't see the appropriate lines.
RH side of the bike above the footbrake master cylinder on the main frame assembly is a black slotted plastic section. Shine your torch into the slot looking rearward and you should see the green glow of your coolant in the reservoir tank along with the Hi and Low level markings I found using a touch thought the top of tank helped see these marks (picture from google search)
