yellow stains on leather and vinyl

In got a new riv and it has this yellow stains on the drivers side of the car, I didn't wanna touch it before I ask around what could remove it, maybe one of you guys knows? don't want to ruin the leather.

also if anyone knows what thuis could be from? looks yucky

Damn.....

The ones towards the front look like someone with really greasy legs wore shorts a lot, not sure about the back. I use both Lexol Cleaner and Lexol Conditioner but I don't know if it could remove something like that. Maybe steam cleaning at a detailer?