Some frames don't allow enough clearance to get the cover off like the manual explains. I had one TT600 that didn't, and I have one that does…I don't know why.
The trick is to support the oil pan with a jack, remove the front and rear upper engine mount bolts (3 in all) and loosen the bottom engine mount bolt. Lower the jack a little bit at a time and the engine will roll down and away from the frame. You may have to press on the engine a bit while snaking the cam cover off. Be careful not to scrape the cam cover on the timing chain, as it would not be good to get gasket or aluminum debris down in the engine there.
Be extremely careful with how the bike is secured while doing all of this! Also, watch out for the aluminum spacer on the rear upper engine mount bolt (you need to put that back in and it's easy to miss). You've got the manual, so take a look at it also, but that's the gist. Good Luck!