Changing primary key column type from varchar to integer
Hunker down and write the script. What you're describing isn't difficult just a little time consuming.

I'd normally recommend to install SQL Server Data Tools; create a new database project by pointing it at the existing database and doing an import (this populates all the tables, views, procedures, indexes, etc). That will then likely build with little or no changes, and you can then make changes in the designers and see what the change script that it outputs is like.

In this case it's not a complete solution because SSDT will usually abort when it finds data in the tables when you're making large changes. But it might give you something to compare against insofar as dropping and recreating all the dependencies goes.