1. run upgrade advisor against the dts package location - check if can be migrated
2. export as storage file from 2000
3. import into Legacy section in sql 2005
4. make sure you have the 2005_DTS_Comp_2000 patch applied to SP2 so you can edit the package
5. migrate it to sql 2005 - (ensure you have ssis setup - msdb or file system storage)
6. check the migration log as a few errors will be reported here that you need to check!