You could solder 12 wires directly onto each side of the six switches and all would be fine. However, this would have to be done on the tracks-side of the PCB and the buttons could then not be used. This would stop the remote control from being used in its original way.
I chose to work on the other side of the PCB and find suitable connecting points to gain access to the six connections I needed. There were suitable links and holes already in the PCB, so I did not have to do any drilling.
I had some very fine enamelled wire which helped some of the connections, otherwise I just used ordinary insulated connecting wire.
The photos show the work in progress and the final socket.