2005 golf plus 1.6 fsi couple of questions about brakes

[paper schooner]

hello everyone. wss wondering could smb explain how to disconnect the brake hose? also was wondering if my brake piston is in really bad condition?

also was wondering if i need to change brake pins, or is cleaning them near the nut is enough?

im not talking about the grease. this ones obvious. im worried about debris and flakes near the nut

[fluid cliff]

I see a torn piston boot. Also you need to see if the pins and bolts need to be replaced by looking at the service manual