Some basic maintenance such as seals and steam tips can be done by you at home and are quite easy.
major faults which require the machine to be opened such as replacing the tubing means disassembling the machine. Special tools are required to take the steam assembly apart.  Without these tools, there is a high risk of damaging the internals.  It is all repairable but it will need to come back to an authorised service centre for a rebuild.