Welcome to the site !!
What you are going to need is the wiring diagram from the model bike you got the new one from , and your wiring diagram , then you need to decipher the connections to see which one does what for each , if you can match the new one to your plug ins , you can swap connections and then you "should" be ok , otherwise , your only other option is to get one that actually is made for your year/etc.
But you need to determine what each wire does , and if it has the same function as yours , which the diagrams will tell you , if so then you can mix/match and transfer the pins to your plug ins and it should function correctly ... otherwise , as mentioned , your only other option is to locate the correct speedo ... The U.S. models only have a trip meter that is mechanical with a speedometer cable running off the front hub , and it resets after 99.9 miles , no readout , nothing ....
Anyway , hopefully what I suggested will work ....
