wiring my new central air blower motor to existing unit?

my new motor has a purple,black,and yellow, wires/with 2 brown capacitor wires. The unit has a black and red wire. I understand the purple and black wire are high speed and the yellow is low. I dont understand how to hook this up to my new unit. Also this new motor is a 25 cap. and the other is a 5.0. Does this make a difference?