Hi!

It´s very easy, no soldering just swap chip.
The hardest part is to open the box and remove the upper circuitboard, the upper row of the connector is attached to this board and you need 2 small screwdrivers to hold the lips in the connector field when you pull out the board.

see link for an overview: http://www.urs4.com/technical/UrS4_MTM1+.html

Note non turbo cars have only one chip.

Happy chipping!