I changed a motor in my Spark, but I don't think I would want to disassemble the innards. Look it up on youtube. Looks to me like something I'd leave for an "expert."
And I work with tiny "SMD" electronic parts.
I change props when some knucklehead (me) damages them doing something knuckleheaded.
Don't worry about them stiff. That's just how they are. Your other brand drone did not have Spark's camera mount and would be more prone to jello with a vibration in the aircraft.
You probably want to stick...