Climbing hold mug

I was very thrilled when I red this article in Climbing.com!
Make Your Own Climbing Hold Mug
How cool is that:
drinking coffee (or something else) out of a mug with a climbing hold instead of a handle.
So I immediately sent my boyfriend to a local flee market where he bought 3 second hand mugs (cost €1,-)
Then I smashed the handles of two of them off with a hammer.
I tried to use sand paper for removing the remaining parts of the handle, what, as I expected, didn’t work out at all.
So I grabbed heavier gear: the angle grinder and supplied it with a grinding wheel for stone.
Although this grinding wheel warned me as it was only for cut-off purposes (not for surface grinding) I thought WTF and used it to remove all the remains of the handle, and I finished the job in a couple of minutes.
Now I have to grind a climbing hold in such a way that is fits on the mug.
I think this will be the hardest part.
To be continued…