What you tried to do manually should have worked... How exactly did you cut the pages in step 2?
If you're interested, though, I've developed a tool that does it automatically for you, within seconds. Have a look here:
Thank you for your answer.
I used the cutting tool from the extended toolbar:
1. double click on the page
2. in the following dialog I set the right border at half the page width (gives the left page)
3. saved that as "left page"
5. double click on the page
6. in the following dialog I set the left border at half the page width (gives the right page)
7. saved that as "right page"
I did that for all the print sheets.