This is a great toturial for anyone who can use a grinder, has a unicycle frame jig and can weld aluminum to repair any broken frame you have! 
Enjoy 
That looks easy.
I’m just looking for my file & soldering iron now so that I can follow that proceedure. I have a vice so I should be set.
Just a quick safety note: Be sure you use a grinder wheel designed for soft metals. Regular ones can pack with the aluminum, overheat and fail spectacularly.
Happy repairs, and thanks for the video, Jakob.
Thanks for the safety note. It’s weird that they never told us that at school! I’m using an aluminum specific blade for the mittering though, but I should get new blades for the first rough part. 