Very very bad idea. Don't climb onto the slide roof - only the main roof with the proper extension ladder plus know how to use it correctly.
DW is a senior manager at our worker's compensation board. People fall off ladders all the time and can end up as paraplegics or quadriplegics. People have even died from falling off just a 4' stepladder. The extent of injuries depends on how you fall and how you hit your head on the ground. You do not want to end up like Christopher Reeve.
I fell off a lightweight aluminum 6' stepladder 20+ years ago and I still have pain from it and affects my sleep.
There is a spike in ladder injuries this time of year with homeowners putting up Xmas lights because they weren't paying attention, not using the right ladder, not using it correctly or doing something they shouldn't be like reaching way out to one side.
Do it right or not at all. It's just not worth the risk.