Vauxhall Opel Astra H 1.3 CDTI

Hey, i have an astra h 1.3cdti and i broke the liitle screen of the speedometer so i was wondering if i could just buy a used one from ebay and desolder my original chips (also dont know what chips need to be desoldered) and resolder them to the new speedometer, you think that is gonna work? Will the immobiliser and mileage work fine like before? Please i need your help!!!'