The decades are planning so the process happens fast. There is a lot that needs to happen correctly to do this fast.
I could personally switch a track guage - but it would be multiple days per km of track switched, if you trained me on how to do this I could do it much faster (I have no idea how much faster, but faster). Train a lot of people like me and it is faster. Or you could buy machines.
We also need to switch all the train wheels, again, not hard - but not something an untrained person can do quickly.
Most likely a large part of the process is finding other railroads around the world that have the needed equipment that will let them borrow it for a few months (most of which time spent in shipping not using the machines.) there are a lot of railroads with old machines they keep for emergency use that can be pressed into use. There are railroads thinking about buying a new machine that would make the order now (with the options Finland needs) if Finland contributes on the understanding Finland gets it for a few months...
I could personally switch a track guage - but it would be multiple days per km of track switched, if you trained me on how to do this I could do it much faster (I have no idea how much faster, but faster). Train a lot of people like me and it is faster. Or you could buy machines.
We also need to switch all the train wheels, again, not hard - but not something an untrained person can do quickly.
Most likely a large part of the process is finding other railroads around the world that have the needed equipment that will let them borrow it for a few months (most of which time spent in shipping not using the machines.) there are a lot of railroads with old machines they keep for emergency use that can be pressed into use. There are railroads thinking about buying a new machine that would make the order now (with the options Finland needs) if Finland contributes on the understanding Finland gets it for a few months...