I came across the video below in which a chap in Australia demonstrates how to replace the angled outlet pipe in a Karcher pressure washer which was leaking.
As it gives a clear demonstration of what is involved I thought it was worth sharing.
The problem in this case was a straightforward internal leak, not the pulsing leak that sometimes happens which tends to be down to a cracked pump head.
The angled water outlet connection is widely available from dealers such as BuySpares at a reasonable cost.
The part number for the Karcher outlet elbow is 9036703.