Your best bet is to start with Brsseb's Tutorials. I know they make cars and guns but they start by assuming you know nothing about O2 and work from there.
Doing this will give you an understanding of the makeup of the model (ie its really about 14 seperate models some not textured at all) and of the interface.
Then rather than starting from scratch I would download one of the models from the demo, which are in a format that we can edit. Try a search for 'demo models' either here or at
www.flashpoint1985.com forums.
Once you have the demo soldier you can work within that framework keeping all of the selections and the memory LOD intact.