The only way is to find a used one just for parts. Or find compatible parts. I own a 2004 Pagsta Mini Chopper and have not been able to use it since I got a flat on my rear tire.
I contacted the dealer and he told me to forget about buying a tire and that he cannot repair it. His exact words were " Too Bad! You bought one of those, we refuse to fix it." Then he proceeded to tell me I would have better luck with a scooter or to go all the way to Quebec City ( I live in Montreal about 8 to 10 hours away ), there might be someone there who might have a tire for sale. After paying $2700 one would think a flat tire would be the least of the problems. The good news is the engine parts are standard parts and compatible parts can easily be found.
If you are experiencing the famous Pagsta problem with climbing hills, all you need to do is switch the sprocket for a smaller one.
Hope this helps
So far I have been able to purchase parts at johnny pag..his number is 229-446-0078
Chopper Rescue - 2004 TV is rated/received certificates of: Australia:PG
Price Chopper - New Zealand - ended in 2004.
American Chopper The Series - 2003 Dixie Chopper 1 1-26 was released on: USA: 3 May 2004
American Chopper The Series - 2003 Dixie Chopper 2 1-27 was released on: USA: 10 May 2004
If you have to ask you can't afford it. I have a full out custom 2004 Texas Chopper that listed for $39900 and paid $32400 new.
The Critical Hour - 2003 Chopper Rescue 2-3 was released on: USA: 1 August 2004
Toward the rear of the bike on the right hand side of the frame...
American Chopper The Series - 2003 Sleigh Bike 2-12 was released on: USA: 20 December 2004
American Chopper The Series - 2003 I Robot Bike 1 2-3 was released on: USA: 12 July 2004
American Chopper The Series - 2003 I Robot Bike 2 2-4 was released on: USA: 19 July 2004
American Chopper The Series - 2003 NY Jets Bike 1-16 was released on: USA: 2 February 2004