If you have a leaking steam wand due to deposit buildup you cannot get to, this is a pretty easy fix with some metric wrenches and a few screw drivers. Save yourself a bunch on shipping your espresso machine off and not miss a day of your favorite brew.
I had replaced the red gasket that is the usual culprit with no effect. Could not get the rest of the old valve clean enough, so this was the cure. You will definitely need open end wrench for inside grip. Don't forget metric!