Not really too hard. Pretty easy if you have alligator clip jumpers. Hardest part is usually having or stacking the batteries. (fresh 9v is my go to or a lantern batt. @6v or two 6v - to + for 12v makes it easy...( a car battery etc )
Scrap wire inserted into the plug temporarily etc.... You just need to verify the motor spins ok for now. Then the multi-meter, and maybe soldering iron gets put to use for board exploration ( don't panic! For simplicities sake, the diodes are just a one way check valves, transistors just tiny relays, and capacitors a holding tank.)
None of it is really hard, it just gets complicated because there is a lot of items. Focus on the basics and the finer detail can be learned later. It's all pretty logical; and the more basics you learn ,the more you'll realize it.