I've run a couple of the old Spacemaster modules in SM2 so it's not quite as big of a shift, and own pretty much all of them, but I can tell you that:
The old modules use as a background the Terran Star Empire, and often use the political maneuvering within it as reasons why things happen. If you can replace that convincingly, you're already most of the way there.
The modules themselves are very open-plan. They give a background, a run down of key NPCs, a couple of maps... and that's about it. This lends itself to a certain flexibility in how they are completed, but also means it becomes easier to drop them into other games.
All of the modules come with rules to convert them to other systems like d20 or Traveller, so I'm guessing they were written with the intent that they got adapted.
In all, it's a bit of work, but a good GM project I'd say!