Aye Alno,
Firstly, you should have a read of the Haynes, Clymer and Ducati workshop manuals, all are readily available, either from an online auction site, bookshop, or the likes of Lacey Ducati Spares, UK.
Also, if you use the 'Search' window in the top right of the Motoscrubs window, you will find numerous threads dealing with shimming and the methodology. I entered "shimming" into the 'Search' window and came up with this selection in this link:
Motoscrubs_'Search'_keyword_"shimming"This should get you started. The correct order, accurate measurement of the components and patience, lots of it, are required, but once done, a lot of satisfaction.
If you get disconbobulated, you can always ask, back on this thread.
Good health, BillR