The manoeuvring system being a system and not a control is approached differently.
If an owner requires the servicing of an existing hydraulic - pneumatic system instead of upgrading it with a new electronic one, then MAS:
Disassembles all elements of the system from the vessel
Services each element separately and checks it for proper operation
Reassembles the elements on the vessel
Adjusts the system to its original condition
Commissions it
It must however be stated that more than once the cost of such a procedure is such that it is to the advantage of the owner to substitute the existing system with a new, electronic one at a reasonable surcharge.