JD Edwards - Add cost to an asset being depreciated

Hello,

We have an asset that is roughly 7 years through a 15 year depreciation schedule.  We recently purchased an attachment for this asset, which extends its useful life by 2 years.  We are trying to add the cost of this attachment to the original asset to alter the NBV of the asset and the amount that will be depreciated monthly.  Every time we try to alter the useful life or NBV, we are unable to save the information.

I'm very new to JDE and would greatly appreciate some help with this issue, sorry if this is a simple question.

Thanks,

Jason