Transfer of Assets from 8.82 to 9.0

Hi Experts .

I am using SAP Business Oe 8.82 PL 08.

I have upgraded my Database to SAP Business One 9.0 PL 05 ,

i have enabled the Fixed Assets in 9.0 .

Already in 8.82 i have Marked all the Assets Items as Fixed Assets in Item master.

In 9.0 when i view the Item Master , it is showing as "Fixed Asset Indicator".

When i tried Importing Fixed Asset Items through Excel from Data Import utility , it is giving me error as , Item Already exists.

I am aware that my Item Master already consists of Fixed Asset Items , but how to transfer those Items From Item Master Data to Asset master Data.

Require suggestions from Experts.

Regards

Vamsi Krishna