To migrate your CiteULike library to colwiz, you are simply required to input your CiteULike log-in credentials in the import option. Here's how you get to it:
In the desktop library, click on 'import' (top-left).
In the resulting window, select 'Import CiteULike'. You will now be asked to log in with your CiteULike account.
Input your CiteULike credentials in the fields provided and the import process will begin.
Once the process is complete, your CiteULike library along with its PDFs and folder structure will be imported to colwiz. You can now find them under 'All publications'.