Generate Database, Drop FK/PK constraints and Indexes

I am trying to use the Generate Database option to create two DDLs that will:

1. drop all FK and PK Constraints (By dependency order) and indexes.  

2. create all PK and FK Constraints and indexes.

I do not want to drop tables.

After playing with all the available options, I was able to achieve the FKs and Indexes.  I cannot see how to drop PKs without dropping the corresponding tables.

Help is welcome,

Pierre