Import Solution as unmanaged

Hello,

I am new to MS dynamics and have been trying to import a solution. I have been using the sample code provided in CRM SDK2016 to import a solution which is exported from the same organization. Below are the steps -

1. Create a Solution

2. Add a Web resource

3. Export solution

4. Delete solution (which is created)

5. Import solution.

I am able to complete all these 5 tasks using the sample code. However I want to import the solution as UNMANAGED because the imported solution is always a managed type. I have also not found to the way to import solution as Unmanaged in 2016 Onlne trial version. Please help!