I fixed mine. It wasn't pretty.
First, I found no way of just replacing the original micro USB. One because of its tiny SMD mount, two because it would still break again (no support around it - that metal thing doesn't help that much). And third, because I couldn't find one to buy...
What I did: I soldered four wires on the proper places in the board (keep in mind the D+ and D- are reversed). I removed the 2 '000' resistors and used their seatings for those wires. For the 5v and GND, I scraped the varnish off the board and put the wires there. Then I put the metal brace back and filled the whole thing with hot glue.
Then I hot glued a board outside of the keyboard, with a PCB connector and a full-sized USB type B (the printer one). And a lot of duct tape.
However, now it won't work with faster USB (2+) because my wire "extension" isn't shielded or has the proper impedance. Anyone reading this: use USB cables instead, strip the heads and use the correct colors, keep all the wires with the same length. And keep in mind that the GND and the outside of the USB connector are not the same thing (USB calls that "drain wire", not GND). The other side of the board has an easy GND around, I scraped the finish and put it right there.
https://photos.app.goo.gl/FhPwTzB4GpWLfUJr5