skoda octivia

hi all and firstly happy new year

i have a problem with the heater in my octivia mk1 2004 classic no aircon or climate when i put heater on it work ( blows hot and cold )it blow not very fast then it dies off and stops working leave it for a few second and does the same was thinking it might be the blower faulty are they easy to change and how do i do it and would i be right in saying it could be the resistor as well ant advise would be of great help

many thanks in advance