Depreciation Items no longer in use

I've been rather sloppy with handling old asset items on my depreciation report.  I've run my mobile home park business for upwards of 25 years and have old items on the report which should be removed.  Some have been replaced or just no longer in use.  Sadly, some were replaced in years past.  All of them have fully depreciated.  I thought I would now take the time to try and clean this up, but I'm concerned about putting prior year disposition dates on my tax return.