Importing not working correctly

I am sorry if this has been mentioned before in a discussion.

Importing is not working for me in several modules. It is a pain to re create fields manually. When exporting leads (compulsory fields only) from a existing instance of erpNext - importing the same leads imports successfully into a fresh instance of erpNext. However, no new lead can be added as it says that the field (lead-000001) already exits.

Is there a way around this by for example refreshing the database?

If you want to delete the entire company transactions before uploading into the new database you can do that or you can update the number series.

How do I update the number series?

Please check the link

Thank you Pawan