all your questions answer depends on how brave you are to open the pandoras box. It indeed is not hard but needs some courage if you have never done similar stuff before. I would recommend to open it up and clean it even change it if the motor is bad too. vacum wont work. compressed air might but not likely also it sprays icy liquid sometimes which might cause damage also. its your call
you do it or let pros do it. You cant learn this stuff unless you put your hands in it also
But i dont want to be an influence on you in any means.