There are two main requirements for maintaining your own bike:
1 Information. I have linked in a previous post to a site which has the Spada service manual for download. This is not like a Haynes or Clymer manual, but it has diagrams of the subsystems of the bike, disassembly/assembly sequences, and notes of special tools, sealants and lubricants required. The Honda Common Service Manual is also useful. It is available as a free download, but I can't remember where mine came from. There doesn't appear to be an independently published manual available.
A Google search will provide some information - I found a Japanese site with overhaul pictures and story.
2 Tools. Metric sockets, ring and open ended spanners are required. A good torque wrench is very useful. The spada has many bolts with hex recesses, so hex keyed sockets will be needed; good screwdrivers, and an impact driver.