You find the capacitor and read what's written on the case.
Use Google and select images - enter start run capacitor - look at the pictures - then when you know what it might look like - find it on your mixer and record the details and take a picture of the wiring or draw a diagram.
Then go to Amazon and buy yourself a new one - under £10.
Micro Farads (uF) the important rating - operating voltage either the same or higher - not lower.
I am only guessing that your issue is with the machine's capacitor - I offer the suggestion because it's the easiest and cheapest fix - if it's the motor then that will cost much more.
Looks like 25uF -
There is no warranty expressed or implied in this answer.
Continuing Good Luck...