There is no good way of doing this in SSIS - I'm with Jeff on this one.
If you want to put an SSIS 'wrapper' round it, something like this would work:
1) Exec SQL: Truncate Staging table
2) Dataflow: Insert to Staging table
3) Exec SQL: UPSERT logic to move from Staging to main data table
If you haven't even tried to resolve your issue, please don't expect the hard-working volunteers here to waste their time providing links to answers which you could easily have found yourself.