Gnome 6
You’ll have to climb another roof for this one. There’s a Climbax to the East of the building you can use. Just drive it over and lift yourself up.
Gnome 7
The hardest Gnome for me to find was this one. Mostly because it’s hidden behind large bushes on top of a building. Head to the roof of the Transbay Center and use your Jumper to enter the large square bush in the center. There’s a red sculpture nearby to let you know you’re in the right place.
Gnome 8
Head to the spot on the map. You’ll have to fight through a restricted area that only has like three guards. Once done, you’ll come across some tents with a bathtub nearby. Grab the gnome.
Gnome 9
The point on the map shows you the easiest entry point to grab the next gnome. I actually took the long way when I collected it, which involves a lot of running and fighting a few guards. Just take a boat to this point and drive through. You’ll notice two parked boats to your right with a ladder behind them. The gnome is up the ladder.
Gnome 10
On the roof of the building marked on the map, you’ll find a hackable area that you’ll need your Jumper to navigate. The gnome is inside.
Once you have all 10 of the gnomes you’re ready to complete your quest. Congratulations!