You can do the full db backup ahead of time. You can do a differential just before you do the index changes.
Script out all existing non-clustered indexes ahead of time also. Drop all n-c indexes before dropping the PK. Then create the clustered index. Then recreate all n-c indexes, including the PK.
The index sequence is always: drop n-c first, then clus; create clus first, then n-c.
SQL DBA,SQL Server MVP(07, 08, 09) "It's a dog-eat-dog world, and I'm wearing Milk-Bone underwear." "Norm", on "Cheers". Also from "Cheers", from "Carla": "You need to know 3 things about Tortelli men: Tortelli men draw women like flies; Tortelli men treat women like flies; Tortelli men's brains are in their flies".