Leaking problem Saeco Stratos

[Vito]

Hi, I bought a used Saeco Stratos with 39.000 cups in the counter. The machine works fine but had a minimal leak, I think that comes from the thermoblock because it had a lot of scale around it. I want to change all the seals and the o-ring, but I would like to know if it is too hard to open the thermoblock (somewhere I read that the screws are to tight) or would be better bought a new thermoblock.