IS THERE ANY PROCESS IN ASSET REVALUATION

hi sap guru's,

we are facing a problem for ex

we purchased a asset in 2003 for value 1cr 80lck. but the same value entered in the books is 2cr. Now we want to reduce the price of that asset in our books. Is there any process to do the revaluation.

Kindly suggest me how to reduce the value and give me the steps or any document.related to it.

it's very urgent please help us.