the stock retainers are socket headed bolts. They are difficult to work with in a couple of locations holding on the header to the head.
Studs with nuts will hold better and are easier to work with.The Suzuki exhaust bolt is easy if you have pivoting metric allen sockets.
You might want to research removing the pair valve while you are in there. This will require block off plates sold by most of the site sponsors.
Give yourself some time and take your time, it will go fine.