Fitting the Brightspark Condenser is easy - it simply replaces an insulating gasket in the points assembly (in the MO1 Magneto - I haven't tried fitting one to any other types). This makes replacing one a simple process if it should fail (and you have a spare).
The problem is that the original condenser has to be taken out of the circuit - which doesn't mean it has to be removed, just disabled - whilst allowing the coil's primary winding to still be connected to the points assembly.
The Brightspark Instructions show a couple of methods of doing this . . . . (I hope they don't mind):
And again - in .pdf format:
Removing the old condenser, making up a replacement female contact for the points retaining bolt (3 BA thread) and 'potting' the lot in epoxy whilst keeping everything in line is what takes the time - if you wish to go down that route.
I now understand how magnetos work, which was a big bonus.
My avatar shows the late Len Rich in 1970 with the bike I now have - a 1958 Ariel VH